Roll of optical film laminate, and method and system for manufacturing the same

ABSTRACT

A roll of optical-film laminate that increases accuracy, speed and yield in the production of liquid-crystal display elements. The roll of optical film laminate is for use in an apparatus for continuously producing liquid-crystal display elements. The optical film comprises a polarizing composite film of a laminate having a continuous web of polarizer and a protective film superposed on one side of the continuous polarizer, an adhesive layer disposed on one side of the laminate; and a carrier film superposed on the adhesive layer of the polarizing film in a peelable state. Defective and normal regions in the polarizing film are determined. According to these determined regions, coded information that specifies positions of slit lines to be formed in the optical-film web are recorded on the continuous web.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a Divisional Application of U.S. patentapplication Ser. No. 12/780,518, filed May 14, 2010, which claimspriority from PCT application numbers PCT/JP2008/000987 andPCT/JP2008/003802, respectively filed on Apr. 15, 2008 and Dec. 17,2008, the disclosure of which is hereby incorporated by reference hereinin its entirety.

TECHNICAL FIELD

This disclosure relates to the process for lamination of polarizingfilms on to substrates used to fabricate LCD (Liquid-Crystal Display)displays.

BACKGROUND

For a liquid crystal display element to function, the direction oforientation of liquid crystal molecules between two substrates and thedirection of polarization of polarizers laminated to the substrates mustbe set in a particular relation to each other. In liquid-crystal displayelement technologies, LCDs using a TN (Twisted Nematic) type liquidcrystal were the first to be put into practical use. Recently, LCDsusing a VA (vertical Alignment) type liquid crystal, an IPS (InplaneSwitching) type liquid crystal etc. were put into practical use.Although a technical explanation is omitted, in an LCD using suchTN-type liquid-crystal panel, liquid crystal molecules are providedbetween two upper and lower orientation films having respective rubbingdirections on the inner surfaces of substrates of the liquid-crystalpanel. This means that the liquid crystal molecules are twisted by 90degrees along the optical axis, so that, when a voltage is applied, theliquid crystal molecules are aligned in a direction perpendicular to theorientation films. However, in case where the LCD is designed to allowimages of the same quality to be seen as viewed from right and leftsides of a display screen as those view from directly in front of thedisplay screen, the direction of rubbing on the orientation film at theviewing-side must be 45 degrees (the rubbing direction of the otherorientation film being 135 degrees). It is therefore necessary that thepolarizing sheets made from the polarizing composite films as shown inFIGS. 1A and 1B, for laminating respectively on the front and back sidesof the liquid-crystal panel with adhesive layers must have polarizersrespectively oriented in directions inclined respectively by 45 degreewith respect to a lengthwise or widthwise direction of the displayscreen so as to conform to the rubbing directions.

Therefore, in an optical film for use in producing a liquid-crystalelement of a TN-type liquid-crystal panel, it is required that theoptical film is punched or cut into a rectangular-shaped sheet having amajor side or a minor side determined in accordance with the size of theTN liquid crystal panel and inclined by 45 degrees with respect to theorientation direction of the polarizer, as described in JapaneseLaid-Open Patent Publication No. JP 2003-161935A or Japanese Patent3616866B.

The punching or cutting the optical film into the rectangular-shapedsheet may be collectively referred as “individualized sheet” or “methodand system for manufacturing individualized sheet” for a liquid-crystaldisplay element. The sheet of optical film thus punched or cut isproduced by punching or cutting in the form including the protectivecarrier film so that any exposure of the adhesive layer in thepolarizing composite film contained in the optical film can beprevented. The punched-out or cut sheet of the carrier film may bereferred as “separator”, rather than “sheet of the carrier film”. Thus,the manufacturing process of the liquid-crystal display elementsincludes the first step of peeling the separator from each of the sheetsof optical film to have the adhesive layer exposed. Subsequently, thesheets of the optical film each having the adhesive layer exposed bypeeling the separator are conveyed one-by-one by for example under avacuum suction irrespective of whether the surface protective films arelaminated or not, and laminated to respective ones of a plurality ofliquid-crystal panels. According to the aforementioned manufacturingprocess of the liquid-crystal display elements, it has been requiredthat the punched-out or cut sheet is in the form of an individualizedsheet having four trimmed sides and a certain level of stiffness. Duringthe initial period in the history of the manufacturing process of theliquid-crystal display elements, this polarizing sheet having fourtrimmed sides was generally been known as a “polarizing plate” which isstill used as a common name.

In the manufacturing process of TN-type liquid-crystal display elements,an optical film unwound from a roll of the optical film may besequentially punched or cut in a direction transverse to the feeddirection. However, in this case, it is impossible to obtain a finishedliquid crystal display element simply by laminating the polarizingsheets formed to respective ones of a plurality of liquid-crystalpanels. This is because the polarizing sheets each formed with a majoror minor side extending in a direction 45 degrees cannot be laminatedsequentially to respective ones of the liquid-crystal panels W with thesame posture. Therefore, to provide a finished liquid crystal displayelement by feeding a polarizing sheet formed from a polarizing compositefilm included in a continuous web of polarizing composite film beingfed, a polarizing composite film having a width greater than a majorside of a liquid-crystal panel W is required. Further, polarizingcomposite film must be punched at an angled direction of 45 degrees withrespect to the lengthwise direction into a plurality of individualpolarizing sheet as seen in Japanese Laid-Open Patent Publication No. JP2003-161935A or Japanese Patent 3616866 B. Alternatively, an elongatedpolarizing composite film may be provided in the form of a single sheetby punching or cutting it in a direction 45 degrees inclined withrespect to the lengthwise direction, or by connecting a plurality ofsuch sheets into a film-like configuration, and winding the film to forma roll of the polarizing composite film. The elongated polarizingcomposite film is then used in a process of forming polarizing sheets,by unwinding the polarizing composite film from the roll, and cuttinginto a required size each of the polarizing sheets and laminated to arespective one of a plurality of liquid-crystal panels W. Therefore, allof the above techniques require a system that manufacturesindividualized sheets.

Before VA-type liquid crystal and IPS-type liquid crystal were broughtinto practical use, Japanese Patent Publication No. 62-14810 B disclosedcontinuously feeding an optical film including a polarizing compositefilm. Japanese Patent Publication No. 62-14810 B discloses a techniqueof continuously feeding an optical film which comprises a polarizingcomposite film (called an “elongated polarizing plate”) and a separatorfor protecting an adhesive layer on the polarizing composite film onto aplurality of liquid-crystal panels (called “liquid-crystal cells”) forsmall-size display screens of electronic calculators or the likeutilizing a carrier function of the separator, cutting only a polarizingplate and an adhesive layer while leaving a separator uncut (hereinafterreferred as “half-cut”)”, removing defective sheets of polarizing sheetsin the course of the feeding, sequentially laminating the remainingpolarizing sheets to the liquid-crystal panels, and peeling theseparator off the polarizing sheets. The apparatus may be a so-called“labeler unit”. However, this liquid-crystal panel is an LCD using aTN-type liquid crystal, so that the optical film herein used must be anelongated sheet cut in a direction 45 degrees oblique to thelongitudinal direction of the optical film. This technique cannot bepractically applied directly to an optical film continuous feedapparatus for use in continuous manufacturing of a large-sizeliquid-crystal display element for widescreen televisions because of thewidth of optical film required.

Automation of process for manufacturing liquid-crystal display elementsusing individualized sheets is generally described below. For example,in Japanese Laid-Open Patent Publication No. 2002-23151A, themanufacturing process utilizing such individualized sheets has problemsnot only in that the separators must be removed from respective ones ofthe individualized sheets taken out from the magazine, but also in thatthe individualized sheets are flexible and are easily curved ordistorted while they are being carried under suction, so thatdifficulties have been encountered in maintaining accuracy and speed inautomatic registration and automatic lamination with liquid-crystalpanels. Thus, it will be understood that the individualized sheet isrequired to have a certain level of thickness and stiffness tofacilitate transport under suction and handling for automatic laminatingprocess. For example, Japanese Laid-Open Patent Publication No.2004-144913A, Japanese Laid-Open Patent Publication No. 2005-298208A orJapanese Laid-Open Patent Publication No. 2006-58411A discloses measuresfor addressing such technical problems.

On the other hand, the VA-type and IPS-type liquid-crystal panels arenot designed to arrange liquid crystal molecules in twistedorientations. Thus, in these types of liquid-crystal panels, there is noneed to have the polarization axis of the polarizing sheet oriented 45degrees, but only required to have the polarizing sheets applied to theopposite sides of the liquid crystal display panel oriented with theirpolarization axes crossed at 90 degrees crossing angle. Rather, in thecase of the VA-type and IPS-type liquid-crystal panels, with respect tothe viewing angle characteristics, maximum contrast can be obtainedalong the direction of the polarizing axis of the polarizing sheet, sothat it is preferable that the polarizing sheets have polarization axesoriented in parallel with the longitudinal or transverse direction ofthe liquid crystal panel from the view point of symmetry of the viewingangle characteristics and visibility. Thus, the polarizing sheets thatincluding a polarizing composite film which has been subjected to alongitudinal or transverse stretching can be continuously unwound from aroll and cut along transverse lines to sequentially produce rectangularpolarizing sheets.

Because of the improved viewing angle characteristics, VA-type liquidcrystal or IPS-type liquid crystal are becoming more widely adopted thanTN type liquid crystal. In view of such trend in environments oftechnical developments, proposals have been made such as the onedescribed in Japanese Laid-Open Patent Publication No. 2004-361741A thatare based on use of the VA-type or IPS-type liquid-crystal panels andcomprise steps of continuously feeding an optical film laminate, cuttingan optical film laminate in conformity to the size of a liquid-crystalpanel and sequentially laminating polarizing sheets to respective onesof a plurality of the liquid-crystal panels.

However, the mainstream of manufacture of liquid-crystal displayelements is still based on manufacturing technology utilizingindividualized sheets, due to the following technical problems. Inmanufacturing liquid crystal display elements, a critical technicalchallenge is to detect any defect which may otherwise be retained in thedisplay elements to be formed, and to prevent any defective product frombeing produced. This makes it possible to significantly improvemanufacturing yield. Most of the product defects primarily arise fromdefects inherent in the polarizing composite film contained in theoptical film. However, it is not practical to provide an optical filmafter completely removing all defects contained in individual filmswhich are to be laminated together to form the optical film. The reasonis that, observation of the polarizer, protective film laminated on thepolarizer and an adhesive layer formed on the films indicates that thereare various kinds of defects distributed in 20 to 200 positions over aunit length of the polarizing composite film of 1000 m This means that,under existing circumstances, it is extremely difficult to produce adefect-free optical film. In a finished display, flaws or defects, evenif such a flaw or defect is small, are not permitted. Therefore, if alength of the polarizing composite film with defects are used to form adisplay and a display requires 1 m of film, 20 to 200 defective displaysare produced per 1,000 displays produced.

A proposed preliminary inspection apparatus for use in individualizedsheets is disclosed, for example, in Japanese Patent No. 3974400B,Japanese Laid-Open Patent Publication Nos. 2005-62165A and 2007-64989A.

Japanese Laid-Open Patent Publication 2007-140046A discloses amanufacturing method wherein an optical film (called “polarizing platestock”) is continuously unrolled from a roll of the optical film in theform of a laminated structure. A carrier film (called “releasable film”)is peeled from the laminate of the optical film before the polarizingcomposite film in the optical film is inspected for existence ofdefects, then after the inspection, the polarizing composite film ispunched or cut avoiding positions of defects.

Japanese Patent Application No. 2007-266200 discloses a method and anapparatus for laminating an optical film onto a liquid-crystal panel.The method and an apparatus disclosed in Japanese Patent Application No.2007-266200, however, require steps that cause substantial complexity inthe entire system for laminating but also an increase in the number ofsteps and difficulty in control for each step, and therefore, causecorresponding reduction in the manufacturing speed.

The present disclosure has been made based on the above relateddisclosures and through intensive research and consideration forsignificantly enhancing product accuracy and manufacturing speed, anddrastically improving production yield, in the manufacture ofliquid-crystal display elements.

SUMMARY

The present disclosure relates to a roll of an optical film laminateincluding a polarizing film having an adhesive layer provided thereon.The roll of an optical film laminate adapted to be applied to a front orbackside of a liquid-crystal panel, and a method and system formanufacturing the same.

The present disclosure provides a roll of optical film laminate for usein a continuous manufacturing method and system for liquid-crystaldisplay elements wherein the continuous manufacturing method and systemare configured for unrolling the continuous web of optical film from theroll under tension, forming a plurality of slit lines in the unrolledcontinuous web of optical film along a direction transverse to the feeddirection of the continuous web at a plurality of pairs of upstream anddownstream positions in the feed direction to a depth reaching the innersurface of the carrier film in the optical film laminate, so that, thecarrier film is left uncut under the cut lines, defective polarizingsheets corresponding to defective regions in the polarizing compositefilm and defect-free, normal polarizing sheets corresponding todefect-free or normal regions each having a size suitable for beinglaminated to each of a plurality of liquid-crystal panels, feeding thesesheets by means of the carrier film by holding them in a releasablemanner on the carrier film and during that time, automatically removingthe defective polarizing sheets to allow only the normal polarizingsheets to be fed to the position for lamination with respective ones ofthe liquid-crystal panels, peeling the carrier film and registering thenormal polarizing sheet with a corresponding one of the liquid-crystalpanels, as described below. Specifically, it is an object of the presentdisclosure to provide means for feeding without interruption acontinuous web of flexible optical film which includes a polarizingcomposite film and forming defective polarizing sheets and normalpolarizing sheets corresponding respectively to defective and normalregions previously determined in the polarizing composite film based onthe defects existing in the polarizing composite film having an adhesivelayer for attachment to the liquid crystal panel, and removal means forremoving the defective polarizing sheets before laminating the normalpolarizing sheets to corresponding ones of the liquid-crystal panels, soas to realize an uninterrupted supply of the continuous web of opticalfilm including the polarizing composite film. This makes it possible tosignificantly enhance the product accuracy and manufacturing speed anddrastically improve the production yield, in the manufacture ofliquid-crystal display elements.

The present disclosure is based on findings that solutions of theaforementioned technical problems can be achieved by a roll of anoptical film laminate adapted for use in a continuous manufacturingsystem for a liquid-crystal display element, wherein the continuousmanufacturing system comprises at least a reading unit, a slitting unit,a removal unit and a lamination unit, and adapted to perform, for eachof a plurality of liquid-crystal panels being sequentially conveyed, aprocess comprising forming slit lines in a continuous web of opticalfilm being continuously transported so as to correspond to the pluralityof sequentially conveyed liquid-crystal panels, in a directiontransverse to the feed direction of the continuous web with a slit depthcorresponding to a part of an overall thickness of the continuous web,peeling a portion of the optical film which extends between twolongitudinally adjacent slit lines defined at the upstream anddownstream positions as seen in the feed direction and has a thicknesscorresponding to the slit depth, from the remaining portion of theoptical film, to form a sheet of the optical film, and laminating thesheet to one of the opposite sides of corresponding one of theliquid-crystal panels, wherein the optical film comprises a polarizingcomposite film which includes a laminate of a continuous layer of apolarizer and a protective film laminated on at least one of theopposite surfaces of the continuous layer of the polarizer, and anadhesive layer provided on one of the opposite surfaces of the laminate,a carrier film being laminated in a releasable manner to the adhesivelayer of the polarizing composite film, and wherein the polarizingcomposite film has defective regions and defect-free, normal regions,which have been previously defined based on locations or coordinatepositions of defects existing in the polarizing composite film anddetected by a preliminary inspection, the continuous web of optical filmhaving encoded information recorded thereon, the encoded informationincluding slit position information for specifying positions at whichthe respective slit lines are to be formed in the continuous web ofoptical film by the slitting unit of the continuous manufacturingsystem, based on the defective regions and the normal regions of thepolarizing composite film, the encoded information being readable by thereading unit of the continuous manufacturing system, and wherein thepresent disclosure has the following features based on theaforementioned findings.

The present disclosure provides (1) a roll of an optical film laminateadapted for use in a continuous manufacturing system for aliquid-crystal display element (2) a method of producing a roll ofoptical film laminate for use in a continuous manufacturing system for aliquid-crystal display element (3) a system for producing a roll of anoptical film laminate for use in a continuous manufacturing system for aliquid-crystal display element.

The present disclosure further provides a continuous manufacturingsystem comprising at least a reading unit, a slitting unit, a removalunit and a lamination unit, and adapted to perform, for each of aplurality of liquid-crystal panels being sequentially conveyed, aprocess comprising forming slit lines in a continuous web of opticalfilm being continuously transported so as to correspond to the pluralityof sequentially conveyed liquid-crystal panels, in a directiontransverse to the feed direction of the continuous web with a slit depthcorresponding to a part of an overall thickness of the continuous web,peeling a portion of the optical film which extends between twolongitudinally adjacent slit lines defined at the upstream anddownstream positions as seen in the feed direction and has a thicknesscorresponding to the slit depth, from the remaining portion of theoptical film, to form a sheet of the optical film, and laminating thesheet to one of the opposite sides of corresponding one of theliquid-crystal panels,

The optical film comprising a polarizing composite film which includes alaminate of a polarizer layer and a protective film laminated on atleast one of the opposite surfaces of the continuous layer of thepolarizer, and an adhesive layer provided on one of the oppositesurfaces of the laminate, a carrier film being laminated in a releasablemanner to the adhesive layer of the polarizing composite film, andwherein the polarizing composite film has defective regions anddefect-free, normal regions, which has been previously defined based onlocations or coordinate positions of defects existing in the polarizingcomposite film and detected by a preliminary inspection, the continuousweb of optical film having encoded information recorded thereon, theencoded information including slit position information for specifyingpositions at which the respective slit lines are to be formed in thecontinuous web of optical film by the slitting unit of the continuousmanufacturing system, based on the defective regions and the normalregions of the polarizing composite film, the encoded information beingreadable by the reading unit of the continuous manufacturing system.

The system for producing a roll of an optical film laminate for use in acontinuous manufacturing system for a liquid-crystal display elementcomprising (a) a provisional-optical-film feed unit provided with a rollof the provisional optical film laminate and adapted to feed aprovisional optical film from the roll of the provisional optical filmlaminate, said provisional optical film comprising a polarizingcomposite film including a laminate of a continuous layer of a polarizerand a protective film laminated on at least one surface of thecontinuous layer of the polarizer, and an adhesive layer provided on atleast one surface of the laminate, said provisional optical film furtherincluding a provisional carrier film laminated on the adhesive layer ofthe polarizing composite film, (b) a provisional-carrier-film detachingunit adapted for detaching by winding the provisional carrier film fromthe provisional optical film supplied from the roll of the previouslyprovided provisional optical film, and feeding the polarizing compositefilm with the adhesive layer in an exposed state, (c) a polarizingcomposite film inspection unit adapted to inspect surface and insideportions of the polarizing composite film which has been supplied withthe adhesive layer in the exposed state, to detect a location orcoordinate position of a defect existing in the polarizing compositefilm having the adhesive layer, (d) an optical-film forming unitincluding a lamination mechanism for laminating the polarizing compositefilm having said adhesive layer on said carrier film, said laminationmechanism being adapted to releasably laminate, through the adhesivelayer, a carrier film supplied from a roll of the carrier film on saidpolarizing composite film in which the location or coordinate positionof the defect in the polarizing composite film has been detected andwhich has the adhesive layer, to form a continuous web of an opticalfilm, (e) an information processing device adapted for defining adefective region and a normal region in the polarizing composite filmincluding the adhesive layer, based on the location or coordinateposition of the detected defect existing in the polarizing compositefilm including the adhesive layer and, based on the defective and normalregions, produce encoded information including slit-position informationindicative of positions at which the respective slit lines are to beformed in the continuous web of optical film by the slitting unit of thecontinuous manufacturing system, (f) an information recording unitadapted to record the produced encoded information on the continuous webof optical film, in a manner readable by the reading unit of thecontinuous manufacturing system, (g) a winding drive mechanism adapted,after the encoded information is recorded on the continuous web ofoptical film, to wind the continuous web of optical film into a roll toform a roll of the optical film laminate, and (h) a control unit adaptedto control respective operations of at least theprovisional-optical-film feed unit, the provisional-carrier-filmdetaching unit, the polarizing composite film inspection unit, theoptical-film forming unit, the information processing device, theinformation recording unit and the winding drive mechanism, in aninter-related manner.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is illustrated by way of example, and not bylimitation, in the figures of the accompanying drawings in whichelements having the same reference numeral designations represent likeelements throughout and wherein:

FIGS. 1A and 1B are schematic diagrams showing the structure of anoptical film for use in manufacturing of a liquid-crystal displayelement according to at least one embodiment;

FIG. 2 illustrates a typical example of a liquid-crystal display elementfor a widescreen television having a diagonal screen size of 42 inches;

FIG. 3 is a schematic diagram showing defective regions includingdefects existing in an optical film for use in a liquid-crystal displayelement, and normal regions having no defect according to at least oneembodiment;

FIG. 4 is a conceptual diagram showing a system for continuouslymanufacturing liquid-crystal display elements wherein polarizing sheetsare laminated on liquid-crystal panels through inspection of defects inthe polarizing composite films, without interrupting the feed ofcontinuous web of the optical film being fed;

FIG. 5 is a conceptual diagram showing a continuous manufacturing systemfor liquid-crystal display elements according to one embodiment, whereinthe system comprises an optical-film feed apparatus for feeding acontinuous web of optical film from a roll of the optical film laminate,and a liquid-crystal-panel conveyance apparatus for conveying aliquid-crystal panel to be laminated with a normal polarizing sheet of apolarizing composite film cut by forming slit lines in the continuousweb of optical film being fed;

FIG. 6 is a flow chart showing a manufacturing process or process stepsin the continuous manufacturing system of liquid-crystal displayelements in FIG. 5;

FIG. 7 is a schematic diagram showing the relationship between a controlunit for controlling device of the optical-film feed apparatus and theliquid-crystal-panel conveyance apparatus illustrated in FIG. 5, andencoded information read by a reading unit and processed by aninformation processing device in the continuous manufacturing system forliquid-crystal display elements, according to at least one embodiment;

FIG. 8 is a schematic diagram showing a defective-polarizing-sheetremoval unit comprising (1) a dummy-film drive mechanism disposed in afeed passage for an optical film or (2) a dummy-film drive mechanismadapted to be moved in and away from a gap between a pair of laminationrollers movable closer to and away from each other, in continuousmanufacturing system for liquid-crystal display elements, according toat least one embodiment;

FIG. 9 is a schematic diagram showing the operation of a slit-positioncheckup unit, together with the inspection method for checking adifference between measurement data on an optical-film feed-out distancemeasured based on a slit line formed in the continuous web of opticalfilm being fed, and the position for forming a slit-line read by areading device, in the continuous manufacturing system forliquid-crystal display elements, according to at least one embodiment;

FIG. 10 is a schematic diagram showing the state when encodedinformation recorded on the continuous web of optical film is read bythe reading unit, and a pre-alignment unit, a final-alignment unit, alamination position-directed conveyance unit and a panel-edge detectionunit in the liquid-crystal-panel conveyance apparatus are controlledbased on the encoded information to allow a liquid-crystal panel to beconveyed in a controlled posture, in the continuous manufacturing systemfor liquid-crystal display elements, according to at least oneembodiment;

FIG. 11 is a schematic diagram showing a lamination unit comprising asheet-edge detection unit for detecting a leading edge of a normalpolarizing sheet of a polarizing composite film formed from thecontinuous web of optical film being fed, and straight-ahead-posturedetection unit for detecting an alignment with a feed direction of theformed normal polarizing sheet of the polarizing composite film;

FIG. 12 is a schematic diagram showing a manufacturing method and systemfor a roll of an optical-film laminate, according to at least oneembodiment;

FIG. 13 is a schematic diagram showing a manufacturing method and systemfor a roll of an optical-film laminate, according to at least oneembodiment;

FIG. 14 is a schematic diagram showing a manufacturing method and systemfor a roll of an optical-film laminate, according to at least oneembodiment;

FIG. 15 is a flowchart showing a manufacturing process or process stepsin the manufacturing method and system for a roll of an optical-filmlaminate illustrated in FIG. 12;

FIG. 16 is a flowchart showing a manufacturing process or process stepsin the manufacturing method and system for a roll of an optical-filmlaminate illustrated in FIG. 13;

FIG. 17 is a flowchart showing a manufacturing process or process stepsin the manufacturing method and system for a roll of an optical-filmlaminate illustrated in FIG. 14;

FIG. 18 is a schematic diagram showing a technique of calculating aposition for forming a slit line in a continuous web of optical filmbeing fed to segment a region of a polarizing composite film into adefective region and a normal region, according to at least oneembodiment;

FIG. 19 is a flowchart showing a technique of calculating a position forforming a slit line in a continuous web of optical film being fed,according to at least one embodiment;

FIG. 20 is a flowchart showing another technique of calculating aposition for forming a slit line in a continuous web of optical filmbeing fed, according to at least one embodiment;

FIG. 21 is a flowchart showing yet another technique of calculating aposition for forming a slit line in a continuous web of optical filmbeing fed, according to at least one embodiment;

FIG. 22 is a table showing an example of encoding and recording ofpositional information to an optical film, according to at least oneembodiment;

FIG. 23 is a diagram showing an example of encoding of a slit-positioninformation indicative of the position for forming a slit line in anoptical film, in a technique of combining identification information ora defect-including information X_(γ) in FIG. 19;

FIG. 24 is a diagram showing an example of encoding of a slit-positioninformation indicative of the position for forming a slit line in anoptical film, in a technique of modifying a distance to a next-slit-lineformation position to (X′+X₀), wherein X₀′>X₀, in FIG. 20;

FIG. 25 is a diagram showing an example of encoding of a slit-positioninformation indicative of the position for forming a slit line in anoptical film, in a technique of modifying a distance to a next-slit-lineformation position to [(X′+X₀)/m], wherein m=2 or more, in FIG. 21;

FIG. 26 is a schematic diagram showing a manufacturing system for a rollof an optical-film laminate having two inspection units, according tothe embodiment illustrated in FIG. 13;

FIG. 27 is a schematic diagram showing a manufacturing system for a rollof an optical-film laminate having four inspection units, according tothe embodiment illustrated in FIG. 14; and

FIG. 28 is a table showing a defect inspection device, a type of defectand a defect detection method.

EXPLANATION OF NUMERICAL CHARACTERS

The following numerical characters are used throughout the descriptionto refer to the following features

-   -   1: continuous manufacturing system for liquid-crystal display        element    -   10: optical film laminate    -   10′, 10″: roll of provisional optical film laminate    -   11: polarizing composite film    -   11′: polarizing sheet    -   12: adhesive layer    -   13: surface-protection film    -   13′: provisional surface-protection film    -   14: carrier film    -   14′: provisional carrier film    -   20: encoded information    -   100: optical-film feed apparatus    -   110: support rack    -   120: reading unit    -   130, 170: film feed unit    -   140: speed adjustment unit    -   150: slitting unit    -   160: slit-position checkup unit    -   190: defective polarizing sheet removal unit    -   200: lamination unit    -   210: carrier-film take-up drive mechanism    -   220: sheet-edge detection unit    -   230: straight-ahead-posture detection unit    -   300: liquid-crystal-panel conveyance apparatus    -   400: control unit    -   410: information processing device    -   420: storage device    -   500, 700, 800: manufacturing system for roll of optical film        laminate    -   510: polarizer manufacturing line    -   520: protective film manufacturing line    -   525: polarizing composite film manufacturing line    -   530: lamination line or provisional-optical-film feed line    -   540: lamination drive mechanism    -   550: distance measurement device    -   560: inspection unit    -   570: carrier-film lamination mechanism    -   571: support rack    -   572: releasable-film take up drive mechanism    -   575. provisional-carrier-film peeling unit    -   576: provisional-carrier-film take up drive mechanism    -   580: optical-film take up drive mechanism    -   590: image-reading device    -   600: control unit    -   610: information processing device    -   620: storage device    -   630: information recording unit    -   640: surface-protection-film lamination mechanism    -   645: provisional surface-protection-film peeling unit    -   646: provisional surface-protection-film take up drive mechanism    -   710: provisional-optical-film feed unit    -   720: provisional-carrier-film take up drive mechanism    -   730: first inspection unit    -   731: second inspection unit    -   740: control unit    -   741: information processing device    -   742: storage device    -   750: carrier-film feed unit    -   760: carrier-film lamination mechanism    -   770: optical-film take up drive mechanism    -   780: information recording unit    -   810: provisional-optical-film feed unit    -   820: provisional-carrier-film take up drive mechanism    -   830: provisional-surface-protection-film take up drive mechanism    -   840: first inspection unit    -   850: second inspection unit    -   851: third inspection unit    -   852: fourth inspection unit    -   860: control unit    -   861: information processing device    -   862: storage device    -   870: provisional-surface-protection-film feed unit    -   880: carrier-film feed unit    -   890: lamination mechanism    -   891: carrier-film lamination mechanism    -   892: surface-protection-film lamination mechanism    -   910: optical-film take up drive mechanism    -   920: information recording unit

DETAILED DESCRIPTION

In the following detailed description, for purposes of explanation,numerous specific details are set forth in order to provide a thoroughunderstanding of the disclosed embodiments. It will be apparent,however, that the disclosed embodiments may be practiced without thesespecific details. In other instances, well-known structures and devicesare schematically shown in order to simplify the drawing.

A widescreen television liquid-crystal display element, for example, fora diagonal screen size of 42 inches comprises a layered liquid-crystalpanel W which includes a pair of rectangular-shaped substrates eachhaving a size of between 540 to 560 mm in length, between 950 to 970 mmin width and about 0.7 mm (700 μm) in thickness, and a liquid-crystallayer having a thickness of about 5 μm having a transparent electrode, acolor filter etc. that is sandwiched between the substrates, as shown inFIG. 1B. The liquid-crystal display element is typically has apolarizing sheet 11′ commonly referred as “a polarizing plate”adhesively applied to a front side (viewing side) and a back side(backlight side) thereof. The polarizing sheet 11′ is formed from apolarizing composite film 11 that is included in a flexible optical filmlaminate 10 of a laminated structure, as shown in the perspective viewin FIG. 1A. The polarizing sheet 11′ has a rectangular shape with a sizeof between 520 and 540 mm in length by between 930 and 950 mm in width,as shown in the perspective view in FIG. 1B. The liquid-crystal panelstructure employed in the liquid-crystal display element is extremelythin having an overall thickness of about 1.4 mm (1400 μm).

According to the disclosed embodiments, although the substrates areusually formed from glass, this disclosure is not limited to glasssubstrates. Other materials such as plastics or composites made fromvarious glass and plastic materials may be used to form either one orboth of the substrates.

The optical film laminate 10 for use in forming the polarizing sheet tobe laminated to the liquid-crystal panel W typically consists of acontinuous web of flexible film which comprises the polarizing compositefilm 11, a surface-protection film 13 having an adhesive surface, and acarrier film 14. The polarizing composite film 11 includes protectivefilms laminated on the opposite surfaces of the polarizer, and anacrylic adhesive layer 12 formed on the side of the polarizer which isto be laminated to the liquid-crystal panel W. The carrier film 14 isreleasably laminated to the adhesive layer 12 to provide a function ofprotecting the exposed side of the adhesive layer 12. Typically, thepolarizing composite film 11 is prepared by subjecting a PVA (polyvinylalcohol)-based film having a thickness of about 50 to 80 μm to a dyeingtreatment using iodine and a cross-linking treatment; subjecting theobtained PVA-based film to an orientation treatment based on stretchingin a lengthwise or widthwise direction thereof to form a continuouspolarizer layer having a thickness of 20 to 30 μm, laminating aprotective film to one or each of the opposite surfaces of the formedcontinuous polarizer layer with an adhesive, and forming an acrylicadhesive layer 12 on one side of the polarizer to be laminated to theliquid-crystal panel W. Generally, a transparent TAC(triacetylcellulose)-based film having a thickness of about 40 to 80 μmis often used as the protective film for protecting the polarizer. Inthe following description, the continuous polarizer layer will be simplyreferred as “polarizer”.

According to the definition of terms in “SEMI (Semiconductor Equipmentand Materials International) Draft Document” on “FPD Polarizing Films(Polarizing Films for Flat-Panel Display Elements) includingliquid-crystal display elements”, the term corresponding to the“polarizing film and layer” constituting an optical film for use in aliquid-crystal display element is referred as “films and layer composingpolarizing films”. Thus, the polarizing composite film 11 in theperspective view as shown in FIG. 1A is interpreted as corresponding tothe “film composing polarizing film”, and the polarizing sheet 11′ inthe perspective view as shown in FIG. 1B is interpreted as correspondingto the “polarizing composite film”. Thus, it is preferable to apply theterm “polarizing sheet” to the polarizing sheet 11′, rather than theterm “polarizing plate”. In the following description, a film includinga polarizer, a protective film laminated on one or both of oppositesurfaces of the polarizer, and an adhesive layer formed on a side of thepolarizer to be laminated to a liquid-crystal panel W, will be referredas a “polarizing composite film”, and a sheet commonly called“polarizing plate”, which is formed in a rectangular shape from thepolarizing composite film, will be referred to as a “polarizing sheet”.

With regard to the thickness of the polarizing composite film 11, apolarizer typically has a thickness of between 20 and 30 μm, and, incase where two protective films are laminated on respective oppositesurfaces of the polarizer, the resulting laminate is increased inthickness by between 80 and 160 μm. Further, an adhesive layer 12 formedon one side of the polarizer to be laminated to a liquid-crystal panel Whas a thickness of between 10 and 30 μm. The thickness of the polarizingcomposite film 11 is, therefore, increased to between 110 and 220 μm intotal. The polarizing composite films 11 are laminated to respectiveones of the front and back sides of the liquid-crystal panel W in such amanner that polarizing axes are set at an angle of 90 degrees to oneanother. Thus, for example, in manufacturing a liquid-crystal displayelement for a widescreen television having a diagonal screen size of 42inches, assuming that a thickness of a liquid-crystal panel itself isabout 1400 μm, and that the thickness of each of the polarizingcomposite films 11 is in the range of 110 to 220 μm, the liquid-crystaldisplay element has an overall thickness of between 1620 and 1840 μm.This overall thickness is still 2.0 mm or less. Thus, the ratio of thethickness of the liquid-crystal element to the overall thickness of theliquid crystal panel W and the polarizing sheets 11′ is between 10:1.5and 10:3. If a polarizing composite film 11 having a protective filmlaminated on only one surface of the polarizer, and an adhesive layer 12formed on the other surface of the polarizer is used, then the thicknessof the polarizing composite film 11 itself can be reduced to 70 to 140μm, so that an overall thickness of the resultant liquid-crystal displayelement is reduced to a range of between 1540 and 1680 μm. The ratio ofthe thickness of the liquid-crystal element to that of the liquidcrystal panel W and the polarizing sheet 11′ will then be in the rangeof between 10:1 and 10:2.

An optical film laminate 10 for use in a liquid-crystal display elementhas a structure as shown in the perspective view in the FIG. 1A. Thestructure of the optical film laminate 10 is briefly described below, inconnection with a manufacturing process thereof. An adhesive surface ofa surface-protection film 13 having a thickness of about 60 to 70 μm isreleasably laminated to the surface of a polarizing composite film 11devoid of an adhesive layer. A carrier film 14 is releasably laminatedto the adhesive layer 12 provided on the surface of the polarizingcomposite film 11 to protecting the adhesive layer 12. Typically, a PET(polyethylene terephthalate)-based film is used for each of thesurface-protection film 13 and the carrier film 14. During themanufacturing process of the liquid-crystal display element, the carrierfilm 14 generally serves as a carrying medium (carrier) for thepolarizing composite film 11, as well as the means to protect theadhesive layer 12. A film having such functions will hereinafter bereferred as a “carrier film”. The thickness of the adhesive layer 12 istypically in the range of 10 to 30 μm. In a process of manufacturing aplurality of such liquid-crystal display elements, a continuous web ofthe optical film laminate 10 is continuously transferred and a pluralityof slit lines are formed along transversely directed lines to a slitdepth corresponding to a part of an overall thickness of the continuousweb, such as a depth reaching the inner surface of the carrier film. Theportion of the polarizing composite film 11 in the optical film laminate10 between two adjacent slit lines at the upstream and downstream sidesas seen in the feed direction of the continuous web (for example, thelines defined by cutting only through the polarizing composite film 11while keeping the carrier film 14 uncut), is peeled to form thepolarizing sheet 11′, and the peeled polarizing sheet 11′ is laminatedin a sequential manner to one surface of one of a plurality ofliquid-crystal panels W being sequentially conveyed Thesurface-protection film 13 and the carrier film 14 that protect therespectively the non-adhesive surface and the adhesive surface of thepolarizing composite film 11 in the continuous web of optical filmlaminate 10 are so-called “manufacturing-process material” which are tobe peeled and removed prior to the final stage of the manufacturingprocess of the liquid-crystal display element.

In the polarizing composite film 11, one of the protective films forprotecting the polarizer may be replaced with a phase difference filmmade of a cycloolefin-based polymer, a TAC-based polymer or the like andhaving an optical compensation function. The protective films mayfurther be provided as a layer of a transparent substrate, such as aTAC-based substrate, having a polymer material, such as apolyester-based polymer or a polyimide-based polymer applied/arrangedthereto and then cured. Further, in the case of a polarizing compositefilm to be laminated to the backlight side of the liquid-crystal displayelement, it may be possible to provide an additional function bylaminating a brightness enhancement film to the backlight sideprotective film of the polarizer. In addition, regarding the structureof the polarizing composite film 11, there have been proposed variousother variations, such as a technique of laminating a TAC-based film toone of opposite surfaces of the polarizer and laminating a PET film tothe other surface of the polarizer.

One of methods for providing a polarizing composite film 11 including apolarizer and a protective film laminated on one or both of oppositesurfaces of the polarizer with an adhesive layer 12 for attaching to aliquid-crystal panel W, comprises laminating a carrier film 14 having atransferable adhesive layer formed thereon, to the surface of thepolarizing composite film 11 to be laminated to the liquid-crystal panelW. A specific transfer technique is as follows. In a manufacturingprocess of the carrier film 14, the carrier film is subjected to areleasing treatment at the surface which is to be laminated to thepolarizing composite film 11 at the surface of the polarizing compositefilm 11 which is to be laminated to the liquid-crystal panel W, and thena solvent containing adhesive is applied to the treated surface anddried to form an adhesive layer on the carrier film 14. Then, thecarrier film 14 having the previously formed adhesive layer 12 islaminated to the polarizing composite film 11, for example, whilecontinuously feeding the carrier film 14 unrolled from a carrier filmroll and feeding the polarizing composite film 11 in the same manner, sothat the adhesive layer formed on the carrier film 14 can be transferredto the polarizing composite film 11. It is understood that the adhesivelayer 12 may be formed by directly applying an adhesive containingsolvent to the surface of the polarizing composite film 11 to belaminated to the liquid-crystal panel W, and drying the same.

The surface-protection film 13 typically has an adhesive surface layer.Unlike the adhesive layer on the polarizing composite film 11, theadhesive surface layer must be peeled off the polarizing sheet 11′together with a sheet (not shown) of the surface-protection film 13 whenthe sheet of the surface-protection film 13 is peeled off the polarizingsheet 11′ during the manufacturing process of the liquid-crystal displayelements. The reason is that the sheet of the surface-protection film 13is provided for protecting the surface of the polarizing sheet 11′, butnot for providing an adhesive surface to the polarizing sheet 11′. Theperspective view as shown in FIG. 1B shows the state after the sheet ofthe surface-protection film 13 is peeled and removed. It should furtherbe noted that, irrespective of whether the polarizing composite film 11has a surface-protection film laminated thereon, it may be possible toprovide the polarizing composite film 11 at the surface of theprotective film on the front side of the polarizing composite film witha hard coat treatment for protecting the outermost surface of theliquid-crystal display element, and/or a surface treatment for obtainingan anti-glare effect or the like, such as an anti-glare treatment.

I. Continuous Manufacturing System and Method for Liquid-Crystal DisplayElement

(General Description of a Continuous Manufacturing System forLiquid-Crystal Display Element)

FIG. 5 is a schematic diagram showing a continuous manufacturing systemfor liquid-crystal display element 1 which comprises an optical-filmfeed apparatus 100 having a roll of an optical film laminate formanufacturing liquid-crystal display elements according to at least oneembodiment, and a liquid-crystal-panel conveyance apparatus 300 forconveying liquid-crystal panels to be laminated with normal polarizingsheets formed from a continuous web of the optical film fed from theroll. FIG. 6 is a flowchart showing a manufacturing process or processsteps in the continuously manufacturing system for liquid-crystaldisplay element 1 illustrated in FIG. 5.

The optical-film feed apparatus 100 comprises a support rack 110 forrotatably mounting a roll of optical film laminate 10 according to atleast one embodiment, a reading unit 120 for reading encodedinformation, a film feed unit 130 including a feed roller, a speedadjustment unit 140 including a dancer roller for providing a constantspeed film feeding, a slitting unit 150 for forming slits in thecontinuous web of optical film in a direction transverse to the feeddirection of the continuous web with a depth reaching the inner surfaceof the carrier film to form slit lines, a slit-position checkup unit 160for checking the formed slit lines, a film feed unit 170 including afeed roller, a speed adjustment unit 180 including a dancer roller forproviding a constant speed feeding, a defective polarizing sheet removalunit 190 for peeling and removing a slit defective polarizing sheet fromthe carrier film, a lamination unit 200 including a pair of laminationrollers for applying a normal polarizing sheet which has been slit andpeeled from the carrier film to a liquid-crystal panel, a carrier-filmtake-up mechanism 210 for taking up the carrier film, a sheet-edgedetection unit 220 for detecting a leading edge of the optical film at alamination position, and a straight-ahead-posture detection unit 230 fordetecting an alignment with a feed direction of the normal polarizingsheet formed by slit lines in the continuous web of optical film.

(Provisions of the Roll of Optical Film Laminate 10)

It is preferable that the roll of optical film laminate 10 according tothis embodiment installed in the optical-film feed apparatus 100 has awidth approximately equal to a length of a long or short side of aliquid-crystal panel to which it is applied. It is preferable that atransparent protective film is used for the protective film laminated onone or each of the opposite surfaces of the polarizer as shown in theschematic diagram of FIG. 1. The roll of optical film laminate 10comprises a roll of optical film laminate comprising a continuous web ofoptical film comprised of a polarizing composite film 11 including apolarizer having an adhesive layer 12 provided on the surface of thepolarizer which has a transparent protective film laminated thereon andwhich is to be attached to a liquid-crystal panel, a surface-protectionfilm 13 having an adhesive surface which is releasably laminated on thesurface of the polarizing composite film 11 opposite to the surfacehaving the adhesive layer 12, and a carrier film 14 releasably laminatedon the adhesive layer 12 of the polarizing composite film 11. Thecarrier film 14 is a releasable film adapted to protect the adhesivelayer 12 of the polarizing composite film 11 during the manufacturingprocess of liquid-crystal display elements and to be removed by beingtaken up when the polarizing sheet formed in the continuous web ofoptical film is peeled off prior to or during lamination process forattaching the polarizing sheet to the liquid-crystal panel. In thisembodiment, the term “carrier film” is used because the film has afunction of carrying the normal polarizing sheets in the optical filmlaminate 10 to the laminating position.

The roll of optical film laminate 10 is formed as follows. Details ofthe manufacturing method for the roll of optical film laminate 10 willbe described below. During the manufacturing process of the roll ofoptical film laminate 10, defects existing in the polarizing compositefilm 11 are first detected in the continuous web of optical film beingcontinuously fed using an inspection unit. Then, based on the detectedlocations or coordinate positions of the defects in the polarizingcomposite film 11, defective regions and defect-free, normal regions aredefined in the polarizing composite film 11 as shown in FIG. 3. Then,information including slit-position information, and optionallyidentification information for identifying the defective regions and thenormal regions is recorded on the continuous web of optical film beingcontinuously fed. The slit-position information is provided forindicating the positions at which respective ones of the slit lines areto be formed in the continuous web of optical film, and the slit linesare formed in pairs by the slitting unit 150 of the continuousmanufacturing system 1 based on the defective and normal regions of thepolarizing composite film 11, during the manufacturing process ofliquid-crystal display elements, in a manner as to slit the continuousweb of optical film being fed in a direction transverse to the feeddirection of the web to a depth reaching the inner surface of thecarrier film so that slit lines are formed at upstream and downstreampositions as seen in the feed direction. The information including theslit-position information and the optional identification information tobe recorded on the continuous web of optical film is encoded informationcreated together with or in association with additional information,such as information relating to the manufacturing lot and the length ofthe web in the roll. Preferably, the encoded information is recorded onthe carrier film 14 in the continuous web of optical film to becontinuously fed. It is to be understood that the encoded informationmay be recorded on the carrier film 14 in any of variety of modes, suchas a mode in which encoded information including all necessaryinformation is recorded at a single location, or a mode in which aplurality of encoded information each including different information isrecorded on a plurality of storage locations at given intervals (e.g.,at intervals of 1 m or 100 m). The encoded information may be recordedon the surface-protection film 13, instead of the carrier film 14. Ineither case, the encoded information is configured to be readable by thereading unit 120 of the continuous manufacturing system 1.

The slitting unit 150 provided in the continuous manufacturing systemfor liquid-crystal display element 1 having the roll of optical filmlaminate 10 mounted thereon is operated, during the manufacturingprocess of the liquid crystal display element, by having the measurementdata on an optical-film feed-out distance calculated when the continuousweb of optical film is unrolled from the roll of optical film laminate10 related with the slit-position information included in the encodedinformation and read by the reading unit 120 of the continuousmanufacturing system 1. The region of the polarizing composite filmdefined by adjacent two slit lines may include a defect-free, normalregion having a give length determined by the length of a side of aliquid-crystal panel to be laminated with the polarizing composite film,and a defective region having a length generally less than the givenlength. During the manufacturing process of the liquid-crystal displayelement, the defective region of the polarizing composite film 11 whichis cut along pairs of slit lines by means of the slitting unit 150 isdefined as a defective polarizing sheet X_(β) which is to be removedfrom the continuous web of optical film (specifically, the carrier film14) by the defective polarizing sheet removal unit 190 of the continuousmanufacturing system 1. The normal region of the polarizing compositefilm 11 is cut in the same manner and defined as a normal polarizingsheet X_(α) which is peeled off from the continuous web of optical film(specifically, the carrier film 14) and laminated to one of oppositesurfaces of a liquid-crystal panel by means of the lamination unit 200of the continuous manufacturing system 1.

In the manufacturing process of a roll of optical film laminate 10, thenormal region is previously defined in accordance with the locations orthe coordinate positions of defects in the polarizing composite film 11as described below, and the length (X_(α)) of the normal region isdetermined to a constant value in accordance with the length of one ofthe sides of the liquid-crystal panel which is to be laminated with thenormal polarizing sheet. Similarly, with respect to the defectiveregion, the upstream side slit line for defining the defective region isdefined by the downstream side slit line defining the normal regionwhich is located immediately upstream side of the defective region, asseen in the feed direction of the web. Thus, the length (X_(β)) of thedefective region is determined by the upstream side slit line and adownstream side slit line which is formed slightly downstream side ofthe location or coordinate position of a defect. Because the lengthbetween the upstream slit line of the defective region and the locationor coordinate position of defects may not be fixed, the length (X_(β))of the defective region varies accordingly. In accordance with at leastone embodiment, the length (X_(β)) of the defective region is determinedby information processing, when a processing is carried out fordetermining the slit position information which designates the positionat which the slit line is to be formed, so that it is always differentfrom the length (X_(α)) of the normal region, e.g., to establish therelationship X_(β)<X_(α), in any case. In accordance with anotherembodiment, it may be possible that information X_(γ) is produced toidentify the defective region over the normal region, when the length(X_(β)) of the defective region becomes equal to the length (X_(α)) ofthe normal region. In this case, the produced identification informationX_(γ) is incorporated into the encoded information together with and inassociation with the slit-position information. It may be possible thatthe continuous manufacturing system 1 is configured such that, duringthe manufacturing process of liquid-crystal display elements, theslitting unit 150 of the continuous manufacturing system forliquid-crystal display elements 1 functions to form the normalpolarizing sheet X_(α) and the defective polarizing sheet X_(β)according to the slit-position information read by the reading unit 120of the continuous manufacturing system 1, and the defective polarizingsheet removal unit 190 of the continuous manufacturing system 1functions to readily discriminate and remove only defective polarizingsheets having lengths (X_(β)) different from the length (X_(α)) of thenormal region. In case where the encoded information includes theidentification information X_(γ) for identifying the defective regionover the normal region, the defective polarizing sheet removal unit 190of the continuous manufacturing system 1 functions, based on theidentification information, to discriminate and remove only defectivepolarizing sheets.

The roll of optical film laminate 10 is mounted on the support rack 110of the optical-film feed apparatus 100. Preferably, the support rack 110is provided with an encoder (not shown) for determining the feed-outdistance of the continuous web of optical film, the measurement dataobtained by the encoder is stored in a storage device 420 of a controlunit 400. Alternatively, a measurement device may additionally beprovided in the optical-film feed apparatus 100 for calculating thefeed-out distance of the continuous web of optical film.

In operation of the entire continuous manufacturing system 1, a roll ofdummy film is first installed on the continuous manufacturing system forliquid-crystal display element 1. A continuous web of dummy film is fedfrom the roll of dummy film under tension by means of first and secondfilm feed units 130, 170 each including feed rollers. The continuous webof dummy film is advanced until its leading edge reaches a positionwhere, under a normal operation, the normal polarizing sheet X_(α) ispeeled off from the carrier film 14, the carrier film 14 from which thenormal polarizing sheet is peeled off is passed through the laminationunit 200 and taken up by the carrier-film take-up drive mechanism 210.Then, the trailing end of the continuous web of dummy film is connectedto the leading end of the continuous web of optical film, and a feed ofthe continuous web of optical film is initiated. In order to allow thecontinuous web of optical film to be fed at a constant speed undertension even if the feed of the continuous web of optical film istemporarily stopped at a position where the slit lines are formed in thepolarizing composite film by the slitting unit 150 of the continuousmanufacturing system 1 or at a lamination position where the normalpolarizing sheet X_(α) is laminated to a liquid-crystal panel, there areprovided first and second speed adjustment units 140, 180 each includingthe aforementioned dancer rollers immediately before these positions.

In the continuous manufacturing system for liquid crystal displayelement 1, assuming that a single roll of optical film laminate 10includes 1000 meters of length of the web of the laminate for example,and the production capacity of the continuous manufacturing system 1amounts to of the order of 5,000 to 20,000 meters a day, a single suchcontinuous manufacturing system 1 will be operated by being sequentiallyconnected with 5 to 20 rolls of the optical film laminate in a day. Inthis case, it can be said that the continuous manufacturing system 1using the roll of the optical film according to this embodiment makes itpossible to enhance product accuracy and double the manufacturing speed.If a plurality of liquid-crystal panels W can be sequentially fedwithout any problem, the number of the rolls of the optical filmlaminate to be handled will increase significantly, which gives rise toa new technical need for automatic replacement of the roll of theoptical film laminate

(Reading and Information Processing of Encoded Information)

In this embodiment, the normal polarizing sheet of the polarizingcomposite film 11 cut along two adjacent slit lines in the continuousweb of optical film is peeled off from the carrier film 14 immediatelybefore the lamination unit 200, and the normal polarizing sheet havingthe exposed adhesive layer 12 is laminated to a liquid-crystal panel bythe adhesive layer 12. During this process, the carrier film 14 is takenup by the carrier-film take-up drive mechanism 210. Generally, thesurface-protection film 13 is made to be a sheet configuration which isheld together with the normal polarizing sheet of the polarizingcomposite film 11 which is to be laminated to a liquid-crystal panel,and the sheet of the surface-protection film is peeled and removed afterthe final step including cleaning/drying is carried out on theliquid-crystal display element to be produced. Both of the carrier filmand the surface-protection film are manufacturing-process materialsrequired for carrying out the process, but are removed in the finalstage of the manufacturing process and discarded. Thus, it is one of thefeatures of the roll of optical film laminate 10 in accordance with thisembodiment to use such a manufacturing-process material as aninformation storing medium necessary for the manufacturing process. Inthe followings, description will solely be made with regard to anexample wherein only the carrier film is utilized as amanufacturing-process material used for the information storing medium.

FIG. 7 is a schematic diagram showing a relation between the encodedinformation 20 to be read by the reading unit 120 of the continuousmanufacturing system 1 and processed by an information processing device410, and the previously described control unit 400 for controlling eachof the units respectively provided in the optical-film feed apparatus100 (see FIG. 5) and the liquid-crystal-panel conveyance apparatus 300(see FIG. 5) for sequentially conveying the liquid-crystal panels. Inthis case, the encoded information 20 recorded in the roll of opticalfilm laminate 10 includes the slit position information indicative ofpositions where the respective slit lines are to be formed in thecontinuous web of optical film, and optionally identificationinformation for identifying defective regions and normal regions. Duringthe manufacturing process of the roll of optical film laminate 10, thecontinuous web of optical film laminate 10 is continuously fed, anddefects existing in the polarizing composite film 11 included in thecontinuous web of optical film laminate 10 are detected by theinspection unit to determine defective and normal regions in thepolarizing composite film 11 based on the locations or the coordinatepositions of the detected defects, whereby the slit lines are formed inpairs by the slitting unit 150 of the continuous manufacturing system 1,base on the defective and normal regions of the polarizing compositefilm 11, during the manufacturing process of liquid-crystal displayelements, so that the continuous web of optical film is slit in adirection transverse to the feed direction thereof at the two adjacentpositions or the upstream and downstream positions in the feed directionto a depth reaching the inner surface of the carrier film.

As shown in FIG. 7, the encoded information 20 is recorded on thecontinuous web of optical film, preferably on the carrier film. Therecorded encoded information 20 is read by the reading unit 120including a code reader or a CCD camera, and the encoded information 20read in this manner is transmitted to the information processing device410 included in the control unit 400 of the continuous manufacturingsystem 1. As is clear from the control of each unit and themanufacturing process flow illustrated in FIGS. 5 and 6, and theschematic diagram of FIG. 7, the encoded information 20 read by thereading unit 120 is transmitted to the information processing device410, and then the information processing device 410 functions toappropriately process the received encoded information 20. The controlunit 400 is also operable, based on the encoded information 20 processedby the information processing device 410, to systematically controlrespective units included in the liquid-crystal-panel conveyanceapparatus 300, and the optical-film feed apparatus 100, such as theslitting unit 150, the defective polarizing sheet removal unit 190 andthe lamination unit 200, in an inter-related manner.

The outline of the control of the entire system will be described below.Based on the slit-position information included in the processed encodedinformation, the control unit 400 functions to control the operation ofthe film feed unit 130 including the feed rollers to feed the continuousweb of optical film and then control the operation of the first speedadjustment unit 140 to temporarily stop the feed of the continuous webof optical film. Then, the control unit 400 functions to control theoperation of the slitting unit 150 to form slits in the continuous webof optical film in a direction transverse to the feed direction of thecontinuous web of optical film at the two adjacent positions or theupstream and downstream positions in the feed direction to a depthreaching the inner surface of the carrier film 14, to form a pluralityof slit lines in the continuous web of optical film.

The continuous web of optical film having the slit lines formed thereonis transported to the slit-position checkup unit 160 where the slit linepositions on the web are confirmed. Then, the defective polarizingsheets and the normal polarizing sheets formed by the slit lines in thecontinuous web of optical film are identified or discriminated from eachother, for example, based on the difference in length, at the defectivepolarizing sheet removal unit 190 inter-related with the film feed unit170 including feed rollers and the speed adjusting unit 180, and onlythe defective polarizing sheets are peeled and removed from the carrierfilm 14. In the case where encoded information includes theidentification information for identifying the defective polarizingsheets and the normal polarizing sheets, it is possible for thedefective polarizing sheet removal unit 190 to peel and remove only thedefective polarizing sheets from the carrier film 14 based on theidentification information. The continuous web of optical film fromwhich the defective polarizing sheets are removed is then transported bythe carrier-film take-up drive mechanism 210, in synchronization withthe feed of the liquid-crystal panels being sequentially conveyed. Thecarrier film 14 is taken up at a position where the leading edge of thenormal polarizing sheet defined by the slit lines in the polarizingcomposite film reaches the leading edge of the conveyed liquid-crystalpanel, where the normal polarizing sheet is peeled off and thelamination unit 200 including the pair of lamination rollers startslaminating operation to attach the normal polarizing sheet to acorresponding one of the liquid-crystal panels.

The manufacturing process of liquid crystal display elements will now bedescribed with respect to specific operations of the respective unitsoperated by the control unit 400, including the laminating operation ofthe lamination unit 200 to attach the normal polarizing sheet to acorresponding one of the liquid-crystal panels.

(Removal of Defective Polarizing Sheet)

The defective polarizing sheet removal unit 190 is operated under thecontrol of the control unit 400 to identify or discriminate only thedefective polarizing sheet X_(β) having a length different from that ofthe normal polarizing sheet X_(α), or only the defective polarizingsheet X_(β) associated with identification information indicating thatsheet as a defective polarizing sheet, from the carrier film 14 on whichthe normal polarizing sheets X_(α) and the defective polarizing sheetsX_(β) of the polarizing composite film 11 formed by the slit lines arelaminated in a releasable manner in the continuous web of optical film,and peel and remove only the defective polarizing sheet X_(β) from thecarrier film 14. FIGS. 8(1) and 8(2) show such defective polarizingsheet removal units 190 adapted, under control of the control unit 400,to identify or discriminate only the defective polarizing sheets X_(β).

The defective polarizing sheet removal unit 190 in FIG. 8(1) comprises adummy-film drive mechanism 191 having a function of releasably attachingto thereon and peeling off the defective polarizing sheet X_(β) from thecarrier film 14, and a swing mechanism 192 adapted to be activated whenthe defective polarizing sheet X_(β) reaches a position in a feed pathwhere removal of the defective sheet is to be initiated, wherein theswing mechanism 192 is adapted to swingably move the feed path of theoptical film so that the feed path of the optical film is moved towardand away from the dummy-film feed path of the dummy-film drive mechanism191.

The defective polarizing sheet removal unit 190 in FIG. 8(2) isconfigured, under control of the control unit 400, to be moved in aninter-related manner with the lamination unit 200 including the pair oflamination rollers, and comprises a dummy-film drive mechanism 191having a function of releasably attaching to thereon and peeling off thedefective polarizing sheet X_(β), and a swing roller 192 defining adummy-film feed path of the dummy-film drive mechanism 191. Thedefective polarizing sheet removal unit 190 in FIG. 8(2) is differentfrom the defective polarizing sheet removal unit 190 in FIG. 8(1) inthat, in the defective polarizing sheet removal unit 190 in FIG. 8(2),the swing roller defining the dummy-film feed path is disposed adjacentto the pair of lamination rollers of the lamination unit 200, andadapted to be moved in an inter-related manner with the laminationrollers of the lamination unit 200. More specifically, when thedefective polarizing sheet X_(β) reaches the end position (i.e., theremoval initiation position) of the feed path of the optical film in thelamination unit 200, the pair of lamination rollers are moved apart fromeach other, and the swing roller 192 forming the dummy-film feed path ismoved to the gap between the lamination rollers located in spaced-apartrelation. In this instance, the carrier film 14 is taken up by thecarrier-film take-up drive mechanism 210, and the defective polarizingsheet X_(β) peeled from the taken up carrier film 14 is attached to theswing roller.

(Checkup of Slit Lines in the Continuous Web of Optical Film)

In the manufacturing process of the continuous web of optical filmlaminate 10, there are previously defined two regions comprising thenormal region having no defect and the defective region having a defector defects, based on the locations or coordinate positions of defectsexisting in the inspected polarizing composite film 11, and based onsuch regions, the continuous web of optical film unrolled from thelaminate roll has the slit-position information which is in the form ofan encoded information 20, the slit-position information beingindicative of the positions at which the slit lines are to be formed inthe continuous web of optical film being continuously fed during themanufacturing process of liquid-crystal display elements. Theslit-position information is read by the reading unit 120 during themanufacturing process of liquid-crystal display elements, and theslitting unit 150 functions, based on the read slit-positioninformation, to form the slit lines in the continuous web of opticalfilm in the direction transverse to the feed direction. It is apparentthat, if the slit lines are not accurately formed, it will becomemeaningless to control the operation of the slitting unit 150 inassociation with the measurement data about the optical-film feed-outdistance measured during transportation of the continuous web of opticalfilm from the roll of optical film laminate 10.

FIG. 9 is a schematic diagram showing the operation of the slit-positioncheckup unit 160 including the manner of inspection for determining adifference between the position of a slit line actually formed in thecontinuous web of optical film, and the position at which the slit-lineis to be formed as read by the reading unit 120.

Two slit-position checkup units 160 are provided at the upstream anddownstream sides as seen in the feed direction with respect to theslitting unit 150. The film feed unit 170 including the feed rollers isdisposed at the downstream side of the downstream slit-position checkupunit 160, so that the downstream slit-position checkup unit 160functions to restart the feed of the continuous web of optical filmwhich is temporarily stopped when the slit lines are formed. The speedadjustment unit 140 including the dancer roll is disposed at theupstream side of the upstream slit-position checkup unit 160, so that itis possible to maintain the feed of the continuous web of optical filmby the film feed unit 130 including the feed rollers, even if the feedof the continuous web of optical film is temporarily stopped when theslit lines are formed.

Coincidence of the position of the slit line actually formed in thedirection transverse to the feed direction of the continuous web ofoptical film with the position calculated based on the measurement dataabout the optical-film feed length can be affirmed by determiningaccurate positions in the traveling direction (X direction) and thetransverse direction (Y direction) of the optical film. One preferableway is to carry out measurements, at two locations at the opposite sidesof the position of the optical film where the slit line is to be formed,for the deviations in X and Y directions on the position of the formedslit line and the edge of the optical film with respect to referencelines. For example, the slit-position checkup unit 160 may be providedwith a CCD camera to take images of the position of the actually formedslit line and the position of the edge of the optical film and producepicturized images. The reference lines are previously provided in theimage-talking regions. The position of the actually formed slit-line andthe position of the edge of the optical film can be determined bydifferences in contrast in the taken images. Then, a calculation is madeto determine the distance (deviation) between the predeterminedreference lines and the positions of the actually formed slit-line andthe edge of the optical film, and the location and the angular positionof the slitting unit 150 is corrected by moving the position forward orbackward with respect to the feed direction of the continuous web ofoptical film, based on the calculated distance (deviation).

More specifically, as shown in FIG. 6, Steps 3, 4 and 7 are performed tofeed the continuous web of optical film under tension, and in Step 5, aslit line is formed in the continuous web of optical film. Then, afurther step is carried out by the two slit-position checkup units 160to determine whether there is any deviation between the position of theactually formed slit-line of the optical film and the position where theslit-line is to be formed, the latter position being determined based onthe slit-position information read by the reading unit 120, and wherethere is any deviation, Steps 6 and 8 are carried out to correct theangular position and the location of the slitting unit 150, for example,in the following manner.

The manner of the inspection for determining the deviation between theposition of the actually formed slit-line of the optical film and theposition where the slit-line is to be formed as read by the reading unit120 is carried out for example in accordance with the followingprocedures.

(1) Images of the position (X) of the actually formed slit line of theoptical film and two positions (Y1, Y2) of the edge of the optical filmare taken by the CCD camera of the slit-position checkup unit 160, andthe images are picturized for measurement of the position of theactually formed slit-line (X) of the optical film and the positions ofthe edges (Y1, Y2) of the optical film by the differences in contrast.

(2) There is a slit line reference position in the form of a lineextending in Y direction at an intermediate position between a referenceline extending in Y direction at an upstream position as seen in Xdirection in the imaging area of one of the slit-position checkup units160 and another reference line extending in Y direction at a downstreamposition as seen in X direction in the imaging area of the other of theslit-position checkup units 160, and data γ representing the distancebetween the upstream and downstream reference lines is stored in thestorage device 420 via the information processing device 410.Furthermore, there are upstream and downstream reference lines extendingin the X direction in respective ones of the image-taking regions of theslit-position checkup units 160.

(3) A correction value α for the position of the slit-line and acorrection value δ for the angular position of the slit-line arecalculated based on the reference lines and the measured positions ofthe slit-line (X) and the edge of the optical film. The correction valueα for the position of the slit-line in the optical film correspond tothe measured deviation α, or the deviation α between the actualslit-line position (X) and the downstream side reference line extendingin the Y direction. The correction value δ for the angular position ofthe slit line can be calculated according to the following formula,based on the deviations in Y direction of the edge of the optical filmat two positions, or the deviations (β1, β2) of the edge of the opticalfilm with respect to respective ones of the upstream and downstreamreference lines extending in the X direction, and the distance data γbetween the two reference lines.

$\delta = {\cos^{- 1}\left\{ \frac{\gamma}{\sqrt{\gamma^{2} + \left( {\beta_{1} - \beta_{2}} \right)^{2}}} \right\}}$

(4) The storage device 420 is used to store correction values (α, δ) forapplying an instruction to the slitting unit 150 to perform an angularposition correction by a value δ and a positional correction by value αin the X direction based on the measured and calculated data so as tomake the slit line conform to the reference slit-line position extendingin the Y direction

(5) The slitting unit 150 receives instruction from the control unit 400for the next operation of forming a slit line in the optical film toperform a positional correction in the feed direction and an angularposition correction in a crosswise direction with respect to the feeddirection, based on the stored correction values (α, δ).

(6) Thereafter, the slitting unit 150 forms a next slit line in thecontinuous web of optical film.

(Removal of Defective Polarizing Sheet and Lamination of NormalPolarizing Sheet on Liquid-Crystal Panel)

The first feature concerning the roll of optical film laminate 10according to this embodiment is that, in advance of laminating thenormal polarizing sheet X_(α) cut from the polarizing composite film 11contained in the continuous web of optical film being supplied on theliquid crystal panel W, the defective polarizing sheets X_(β) cut fromthe polarizing composite film 11 taken away by the defective polarizingsheet removal unit 190, without interrupting the feed of the continuousweb of optical film and without taking away any normal sheets. Thesecond feature of this embodiment is that only the normal polarizingsheet X_(α) cut from the polarizing composite film 11 can be fed to aposition for lamination with a liquid-crystal panel W by thecarrier-film take-up drive mechanism 210, while eliminating a need forinterrupting the feed of the continuous web of optical film. The abovefeatures are inconceivable in the case of an individualized sheet or inthe manufacture of individualized sheet. It is apparent that the use ofsuch roll of optical film laminate 10 in the manufacturing process ofliquid-crystal display elements leads to a significant increase in thespeed and a significant improvement in accuracy of applying the normalpolarizing sheet X_(α) to the liquid-crystal panel W.

(Transportation of Liquid-Crystal Panel and Lamination with NormalPolarizing Sheet Xα)

Before specifically describing in detail the lamination unit 200including the pair of lamination rollers adapted to be vertically movedtoward and away from each other for laminating the liquid-crystal panelW with the normal polarizing sheet Xα which has been cut from thepolarizing composite film 11, a brief description is made regarding thetransportation or liquid-crystal-panel conveyance apparatus 300 for theliquid-crystal panel W which is to be laminated with the normalpolarizing sheet of the polarizing composite film 11 formed from thecontinuous web of optical film which is also being supplied.

Taking a large size television having a diagonal screen dimension of 42inches as an example, a rectangular-shaped liquid-crystal panel W has asize of between 540 and 560 mm in length and between 950 and 970 mm inwidth. In the manufacturing process of liquid-crystal display elements,the liquid-crystal panel W is slightly trimmed along its peripheriesduring a wiring stage including mounting operations of electroniccomponents. Alternatively, the liquid-crystal panel W may be transportedor conveyed with peripheries already trimmed. The liquid-crystal panelsW are taken out one-by-one from a magazine containing a large number ofliquid crystal panels, by means of a liquid-crystal-panel supplyapparatus, and conveyed through a cleaning/polishing stage to a positionfor lamination with respective ones of the normal polarizing sheet Xα ofthe polarizing composite film, by the liquid-crystal-panel conveyanceapparatus 300, by being adjusted to maintain equal intervals and aconstant transportation speed, for example. The normal polarizing sheetXα is formed from the continuous web of optical film to have a sizeslightly less than that of the liquid-crystal panel W. As shown in FIG.10, in a final station for lamination of the normal polarizing sheet Xαon the liquid-crystal panel W, the liquid-crystal-panel conveyanceapparatus 300 includes a pre-alignment unit 310, final-alignment unit320 for controlling the orientation of the panel, a conveyance unit 330to transport the panel to the lamination position, and a panel-edgedetection unit 340 for detecting the leading edge of the liquid-crystalpanel W.

FIG. 10 is a schematic diagram showing the transportation of the liquidcrystal panels W in an aligned orientation, by means of thepre-alignment unit 310, the final-alignment unit 320, the conveyanceunit 330 for conveying the panels to the lamination position, and thepanel-edge detection unit 340 which are provided in theliquid-crystal-panel conveyance apparatus 300, based on the encodedinformation which is read from the continuous web of optical film by thereading unit 120 during the manufacturing process of liquid-crystaldisplay elements. Further, FIG. 11 is a schematic diagram showing thelamination unit 200 for laminating the polarizing film sheet with theliquid crystal panel W, comprising the sheet-edge detection unit 220 fordetecting the leading edge of the normal polarizing sheet Xα of thepolarizing composite film formed from the continuous web of optical filmbeing fed, and the straight-ahead-posture detection unit 230 fordetecting the alignment with the feed direction of the normal polarizingsheet Xα formed from the polarizing composite film.

Preferably, the normal polarizing sheet Xα is fed to the laminationposition at a constant speed by the carrier film 14. As shown in FIG. 10or 11, at the lamination position, only the carrier film 14 is peeled bybeing bent at an acute angle, by the carrier-film take-up drivemechanism 210. By having the carrier film 14 peeled by being bent at anacute angle, the adhesive layer on the normal polarizing sheet Xα isgradually exposed. This makes it possible to slightly expose the leadingedge of the normal polarizing sheet Xα to allow the leading edge of theliquid crystal panel W to be easily aligned with the leading edge of thenormal polarizing sheet Xα.

As shown in FIG. 10, the leading edge of the normal polarizing sheet Xαis moved to the gap defined between the pair of lamination rollers ofthe lamination unit 200 which are now in the vertically spaced apartrelation to each other, and detected by the sheet-edge detection unit220. Although the normal polarizing sheet Xα is fed in a state laminatedon the carrier film 14, it is seldom that the normal polarizing sheet Xαis accurately fed so that the angle θ between the feed direction and thelengthwise direction of the carrier film 14 becomes zero. Therefore,deviations of the normal polarizing sheet Xα in the feed direction andthe transverse direction are measured, for example, by taking images ofthe sheet using the CCD camera of the straight-ahead-posture detectionunit 230 and subjecting the taken images to an image processing, wherebythe measured deviations are calculated in terms of X, Y and θ, and thecalculated data is stored in the storage device 420 by the control unit400.

Then, the plurality of liquid-crystal panels W are sequentially suppliedfrom the liquid-crystal-panel supply apparatus illustrated in FIG. 5 ateven intervals and a constant speed. The liquid-crystal panels W aresupplied one-by-one and subjected to the alignment control by theliquid-crystal-panel conveyance apparatus 300 illustrated in FIG. 10.This alignment control will now be described with reference to FIG. 10.

The liquid-crystal panels W are sequentially positioned by thepre-alignment unit 310, so that they are aligned in lengthwise andwidthwise directions respectively with the transport direction and thedirection perpendicular to the transport direction in the conveyancepath. The positioned liquid-crystal panel W is conveyed to and placed onthe final-alignment unit 320 which includes an alignment table adaptedto be turned by a drive mechanism which is controlled by the controlunit 400. The leading edge of the liquid-crystal panel W placed on thealignment table is detected by the panel-edge detection unit 340. Theposition of the detected leading edge of the liquid-crystal panel W ischecked for match with the reference lamination position stored in thestorage device, specifically, the calculation data in terms of X, Y andθ to represent the orientation of the normal polarizing sheet Xα to belaminated to the liquid-crystal panel W. For example, the deviationbetween the leading edge of the liquid-crystal panel W and the referencelamination position is measured using an alignment mark of theliquid-crystal panel W illustrated in FIG. 2 to calculate the angulardisplacement θ, and the alignment table having the liquid-crystal panelW placed thereon is turned by the angular displacement θ. Then, thealignment table is connected to the lamination position-directedconveyance unit 330. The liquid-crystal panel W is conveyed to thelamination position while keeping the same orientation, by thelamination position-directed conveyance unit 330, and the leading edgeof the liquid-crystal panel W is registered with and laid on the leadingedge of the normal polarizing sheet Xα. In the final stage, the normalpolarizing sheet Xα and the liquid-crystal panel W which are in alignedrelation with each other are held between the pair of lamination rollersand conveyed thereby to obtain a finished liquid-crystal displayelement.

The normal polarizing sheet Xα is fed to the lamination positiontogether with the carrier film 14 within the continuous web of opticalfilm advanced under tension, so that there is least possibility that theperiphery of the normal polarizing sheet Xα is bent or sagged. Thus, thenormal polarizing sheet Xα is less likely be flexed or bent. This makesit easy to have the liquid-crystal panel W aligned with the normalpolarizing sheet Xα, so that the manufacturing speed of the liquidcrystal display element can be increased and the product accuracy can beimproved. Such method and system could never be applied to themanufacturing process utilizing individualized sheets wherein, afterpeeling a separator from each of the individualized sheets to expose theadhesive layer, and feeding under a vacuum suction each of the sheets toa lamination position, adjusting the position of the sheet with respectto the liquid-crystal panel W, the sheet is laminated to theliquid-crystal panel W to complete a liquid-crystal display element.This is because the aforementioned method and system are related to thecontinuous process for manufacturing liquid-crystal display elementswhich can be implemented only by adopting the roll of the optical filmlaminate according to this embodiment.

II. Roll of Optical Film Laminate, Manufacturing Method and SystemTherefor

Description will now be made regarding the roll of the optical filmlaminate, a manufacturing method and system therefor, according to atleast one embodiment making reference to the drawings.

(Structure of Polarizing Composite Film)

As shown in FIG. 1, the sheet of optical film to be laminated to theliquid-crystal panel is typically comprised of a flexible optical filmincluding a polarizing composite film formed with an acrylic adhesivelayer for lamination with a substrate of the liquid-crystal panel W. Thepolarizing composite film includes a polarizer (continuous polarizerlayer) having a thickness of 20 to 30 μm comprising a substrate made ofa PVA-based film which has been subjected to a dyeing treatment usingiodine and a cross-linking treatment, and thereafter subjected to anorientation treatment by a lengthwise or widthwise stretching, and thepolarizer is provided on one or each surface with a transparentprotective film which is laminated thereon and comprises a substrate ofTAC-based film having a thickness of about 40 to 80 μm for protectingthe polarizer. Typically, an acrylic adhesive layer is formed on theside of the polarizer which is to be laminated to the liquid-crystalpanel W.

(Process Using Conventional Individualized Sheets)

As already described, in an individualized sheet manufacturing process,individualized sheets are prepared by punching or cutting a continuousweb of optical film into sheets of rectangular shape, each beinglaminated with a separator through an adhesive layer. The individualizedsheets each formed into a rectangular shape and laminated with theseparator are stored in a magazine in a liquid-crystal display elementmanufacturing line. Then, in a process of laminating the individualizedsheets with respective ones of a plurality of liquid-crystal panels W,the flexible individualized sheets pre-stored in the magazine areconveyed to a lamination position one-by-one. The separator releasablylaminated to the adhesive layer formed on each of the flexibleindividualized sheets is peeled to expose the adhesive layer, and theindividualized sheet is laminated to a corresponding one of theliquid-crystal panels W through the exposed adhesive layer. During thisprocess, because the individualized sheet is flexible, problems areexperienced in that the periphery of the rectangular-shapedindividualized sheet is bowed or warped. Thus, in a liquid-crystaldisplay element manufacturing process using such individualized sheet,in order to quickly perform alignment and lamination with aliquid-crystal panel with a high degree of accuracy, there is no otherchoice but to use individualized sheets which may have less problem ofbowing or warping. For the purpose, for example, protective films eachhaving a thickness of 40 to 80 μm are laminated to both of the oppositesurfaces of a polarizer, but not to one of the surfaces, to impartstiffness to the individualized sheet by increasing thickness.

(Manufacturing Method and System for Roll of Optical Film Laminate)

FIGS. 12 to 14 are schematic diagrams showing manufacturing methods andsystems for rolls of the optical film including a polarizing compositefilm according to at least one embodiment of the disclosure. FIGS. 15 to17 are flowcharts showing respective manufacturing processes ormanufacturing steps in the manufacturing methods and systems accordingto embodiments of the disclosure.

In the embodiments illustrated in FIGS. 12-14, the polarizing compositefilm 11 constituting the roll of optical film laminate 10 may be made ofa polarizer including a substrate of a PVA based material having atleast one surface laminated with a protective film, preferably of atransparent material, with an adhesive layer 12 provided on the othersurface. A carrier film 14 adopted as a manufacturing-process materialis releasably attached to the adhesive layer 12. In the conventionalliquid-crystal display element manufacturing process usingindividualized sheets, the polarizing composite film used therein hastwo protective films laminated thereon at the opposite surfaces toimpart stiffness to the polarizing sheet. However, in a liquid-crystaldisplay element manufacturing process using the roll of the optical filmin accordance with some embodiments, the normal polarizing sheet X_(α)formed from the polarizing composite film 11 in the roll of the opticalfilm laminate 10 is peeled from the carrier film 14 at the laminationposition, and will gradually separated from the web. It is to beunderstood as a matter of course that there is no need of peeling theseparator on a sheet-by-sheet basis as in the manufacturing processusing the individualized sheets.

When the normal polarizing sheet X_(α) is peeled off the carrier film14, the leading edge of the normal polarizing sheet X_(α) is registeredwith the leading edge of a corresponding one of a plurality ofliquid-crystal panels W being sequentially conveyed toward thelamination position. Then, the normal polarizing sheet X_(α) and thecorresponding liquid-crystal panel W are laminated together by beingpressed against each other by the pair of lamination rollers of thelamination unit 200. In this process, there is no risk that theperiphery of the normal polarizing sheet X_(α) is warped because thesheet is gradually peeled off the carrier film. Thus, differently fromthe individualized sheet, in the polarizing composite film 11 includedin the continuous web of optical film in some embodiments, theprotective film may be laminated to only one of the surfaces of thepolarizer, and additionally it is possible to make the thickness of theprotective film to be 40 μm or less.

Description will now be made of the manufacturing methods and systems ofthe optical-film roll, according to embodiments, making reference toFIGS. 12 and 15, FIGS. 13 and 16, and FIGS. 14 and 17, respectively.

(Manufacturing Method and System for Roll of Optical Film LaminateAccording to the Embodiment Illustrated in FIG. 12)

FIG. 12 is a schematic diagram showing the manufacturing system formanufacturing the roll of the optical film laminate 500 which comprisesa polarizer manufacturing line 510 for producing a continuous polarizerlayer (hereinafter referred to as “polarizer” as in the previousdescription), a protective film manufacturing line 520 for producing aprotective film to be laminated on the polarizer, a polarizing compositefilm manufacturing line 525 for producing a laminate including thepolarizer and the protective film (the laminate will hereinafter bereferred as “polarizing sheet 11” to distinguish it from the polarizingcomposite film 11 which does not have an adhesive layer), andsurface-protection film lamination mechanism 640 for laminating acarrier film and a surface-protection film, to the polarizing compositefilm to produce the optical film. FIG. 15 is flowchart showing themanufacturing process or steps in the manufacturing system 500.

The polarizing composite film manufacturing line 525 includes aninspection sub-line for inspecting a defect existing in the polarizingcomposite film 11 by an inspection unit 560, a carrier film feedsub-line for laminating a carrier film 14 having a transferable adhesivelayer 12 formed thereon, to one of the opposite surfaces of thepolarizing sheet 11′, an information recording sub-line for recordingencoded information including slit-position information, on a surface ofthe carrier film 14, a surface-protection film feed sub-line forlaminating a surface protection film 13 through it adhesive surface tothe surface of the polarizing sheet 11′ opposite to the surface on whichthe carrier film 14 is laminated, and a taking up sub-line for taking upthe continuous web of optical film having the encoded informationrecorded thereon to form a roll of the optical film. The carrier filmfeed sub-line has mounted thereon a roll of the carrier film 14 having areleasing film attached thereto, and the surface-protection-film feedsub-line has mounted thereon a roll of the surface protection film 13having a releasing film attached to the adhesive surface of the surfaceprotection film 13. The slit-position information is obtained byprocessing the information about a normal region having no defect and adefective region having a defect or defects which is previously definedin the polarizing sheet 11′ based on the location or coordinate positionof the defect therein detected at the inspection sub-line, and used to,in forming a normal polarizing composite film and a defective polarizingsheet from the polarizing composite film, designate at least positionsat which slit lines are to be formed in the continuous web of opticalfilm being fed.

The polarizer manufacturing line 510 has a roll of PVA-based film whichconstitute the substrate of the polarizer and is mounted thereon in arotatable manner, and includes a sub-line for subjecting the PVA-basedfilm being unrolled from the roll by means of a lamination drivemechanism 540 or other drive mechanism (not shown), to processes ofdyeing, cross-linking, stretching and then drying. The protective filmmanufacturing line 520 has rotatably mounted thereon a roll of atypically transparent TAC-based film constituting a substrate of theprotective film, and includes a sub-line for subjecting the transparentTAC-based film being unrolled from the roll by means of the laminationdrive mechanism 540 or other drive mechanism (not shown), to asaponifying treatment followed by drying. Each of the protective filmmanufacturing line 520 and the polarizing composite film manufacturingline 525 for the polarizing sheet 11′ includes a sub-line for applyingan adhesive that includes primarily a polyvinyl alcohol-based resin toan interface between the polarizer and the protective film, and dryingthe adhesive to bond them together through an adhesive layer having athickness of only several μm.

The manufacturing line 525 for the polarizing sheet 11′ comprises thelamination drive mechanism 540 including a pair of lamination rollers.The lamination drive mechanism 540 comprises a distance measurementdevice 550 having an encoder incorporated in one of the laminationrollers. The lamination rollers are adapted to laminate the protectivefilm to the polarizer by pressing them against each other, to form apolarizing sheet 11′, and feed the polarizing sheet 11′.

This manufacturing system 500 includes the inspection unit 560 fordetecting defects in the surface and the inside of the polarizing sheet11′ to be fed. It is required to provide the polarizing sheet 11′ withthe adhesive layer 12 only after the defects are detected, to completethe polarizing composite film 11. Therefore, the present manufacturingsystem 500 further comprises a carrier-film lamination mechanism 570having mounted thereon the roll of the carrier film 14 having theadhesive layer 12. The adhesive layer 12 on the carrier film 14 isformed in advance in the manufacturing process of the carrier film 14,by subjecting one of the opposite surfaces of the carrier film 14 whichis to be releasably laminated to one of the opposite surfaces of thepolarizing sheet 11′ to be laminated to the liquid-crystal panel to areleasing treatment, applying to that surface a solvent containing anadhesive, and then drying the solvent. When the carrier film 14 fed fromthe carrier-film lamination mechanism 570 is laminated on the polarizingsheet 11′ in a releasable manner, the adhesive layer 12 previouslyformed on the carrier film is transferred to the polarizing sheet 11′ toprovide the adhesive layer 12 on the polarizing composite film 11.

The manufacturing system 500 further comprises an information recordingunit 630 for recording encoded information, for example, on a surface ofthe carrier film 14. More specifically, the information recording unit630 is operable to record, on a continuous web of optical film being fedduring the manufacturing process of liquid-crystal display elementsusing the produced roll of the optical-film laminate, encodedinformation including the slit-position information indicative of thepositions at which slit lines are to be formed in the continuous web ofoptical film to form normal and defective polarizing sheets of thepolarizing composite film. The manufacturing system 500 may furthercomprise a surface-protection-film lamination mechanism 640 forlaminating a surface-protection film 13 through an adhesive surface tothe surface of the polarizing sheet 11′ opposite to the surface on whichthe carrier film 14 is laminated. Finally, the manufacturing system 500comprises an optical-film take up drive mechanism 580 for taking up theoptical film which is constituted by the polarizing sheet 11′ with thecarrier film 14 having a transferable adhesive layer and thesurface-protection film 13 laminated on the opposite surfaces of thepolarizing sheet 11′.

In the case where protective films are laminated on the oppositesurfaces of the polarizer, the manufacturing system 500 will include twoprotective film manufacturing lines 520, 520′ (the protective filmmanufacturing line 520′ is omitted in the drawing). Further, theprotective film manufacturing line 520 may additionally include atreatment sub-line for subjecting the surface of the protective film toa hard coat treatment and/or an anti-dazzling or anti-glare treatment,before a protective film is laminated to the polarizer.

The inspection unit 560 comprises an image-reading device 590 includingfor example a CCD camera. The image-reading device 590 is electricallyconnected to an information processing device 610 included in a controlunit 600, wherein image data read by the image-reading device 590 isprocessed in association with measurement data measured by the distancemeasurement device 550 electrically connected to the informationprocessing device 610. The control unit 600 functions to operate theinformation processing device 610 and a storage device 620 to processthe image data from the image-reading device 590 in association with themeasurement data based on the delivered length measured by the distancemeasurement device 550 as a length from the leading edge of thepolarizing sheet 11′, so as to produce position data representing thelocation or the coordinate position of the defect in the polarizingsheet 11′, the position data being then stored in the storage device620. The control unit 600 functions, based on the position data on thedetected location or coordinate position of the defect, to define adefective region and a normal region in the polarizing composite film11.

The control unit 600 functions, based on the position data on thedetected location or coordinate position of the defect, to define in thepolarizing composite film 11 a defective region and a normal region.Further, the control unit 600 functions, based on the defective andnormal regions of the polarizing composite film 11, to createslit-position information. The slit-position information is provided forindicating positions at which respective ones of the slit lines are tobe formed in the continuous web of optical film. The slit lines areformed in pairs by the slitting unit 150 during the manufacturingprocess of liquid-crystal display elements, so that the continuous webof optical film being fed is slit in a direction transverse to the feeddirection thereof at the two adjacent positions or the upstream anddownstream positions in the feed direction to a depth reaching to theinner surface of the carrier film 14. The produced slit-positioninformation is also stored in the storage device 620. Then, theinformation processing device 610 functions, based on the storedslit-position information, to create encoded information, together withadditional information, such as information on the manufacturing lot anda length in meters of the optical film in the roll, or in associationwith the additional information. As already mentioned, the encodedinformation is preferably recorded on the carrier film 14 included inthe continuous web of optical film, during the manufacturing process ofliquid-crystal display elements using the optical film roll. It is to beunderstood that the encoded information can be recorded on the carrierfilm 14 in various ways, such as the one in which encoded information isentirely recorded on a single storage location, and the one in whichencoded information is recorded on a plurality of storage areas disposedat given intervals (e.g., at intervals of 1 m or 100 m). Alternatively,the encoded information may be recorded on the surface-protection film13, if any, instead of the carrier film 14.

It is to be noted that the regions defined by respective pairs of slitlines may include a defect-free or normal region having a give lengthdetermined by the length of a side of the liquid-crystal panel to belaminated with the polarizing composite film, or a defective regionincluding a defect or defects having a length usually less than thelength of a normal region. During the manufacturing process of theliquid-crystal display element, it is necessary to allow the slittingunit 150 to cut the defective region and normal region of the polarizingcomposite film 11 along corresponding ones of the pairs of slit linesbased on the slit-position information included in the encodedinformation, so that the defective polarizing sheet X_(β) is removedfrom the carrier film 14 by the defective polarizing sheet removal unit190, and the normal polarizing sheet X_(α) is peeled off the carrierfilm 14 to be laminated to one surface of the liquid-crystal panel W.

Therefore, the length (X_(α)) of the normal region is determined basedon the position data relating to the location or coordinate position ofthe defect existing in the polarizing composite film 11 in accordancewith the length of a side of the liquid-crystal panel to be laminatedwith the normal polarizing sheet, so that the length always has aconstant value. Regarding the defective region which is defined in thesame manner, however, the upstream one of the two slit lines for thenormal region located just upstream of the defective region in a feeddirection can be used as the downstream one of the two slit lines forthe defective region, so that the length (X_(β)) of the defective regionis determined by the downstream slit line and an upstream one which islocated slightly upstream of the location or coordinate position of thedefect. Because the length between the downstream slit line and thelocation or coordinate position of a defect may not be the same, thelength (X_(β)) of the defective region varies. Preferably, a calculationalgorithm for producing the slit-position information indicative of thelocations for forming the slit lines is configured such that the length(X_(β)) of the defective region is different from the length (X_(α)) ofthe normal region, for example, to have a relation X_(β)<X_(α), in anycase, as described below. The procedure of creating the encodedinformation is common in the above embodiments, so that the procedurewill be described below in connection with reference to FIGS. 18 to 28.

The carrier-film lamination mechanism 570 for laminating the carrierfilm 14 to the polarizing sheet 11′ will now be described below. Thecarrier film 14 is previously formed in the carrier film manufacturingline (not shown) using a PET (polyethylene terephthalate)-based film ofabout 20 to 40 μm in thickness as a substrate. A transferable adhesivelayer having a thickness of about 10 to 30 μm can be formed on one ofthe opposite surfaces of the carrier film 14 by, after subjecting one ofthe opposite surfaces of the PET-based film to a releasing treatment,applying a solvent containing an acrylic adhesive to the treatedsurface, and drying the solvent. By having the carrier film 14 laminatedin a releasable manner on the polarizing sheet 11′, the adhesive layeris transferred to the polarizing sheet 11′ to form the optical filmwhich comprises the polarizing composite film 11 having the adhesivelayer. During the manufacturing process of liquid-crystal displayelements using the roll of optical film laminate 10 formed in the abovedescribed manner, the adhesive layer 12 is peeled together with thenormal polarizing sheet of the polarizing composite film 11 is from thecarrier film 14 when the normal polarizing sheet of the polarizingcomposite film 11 is peeled off the carrier film 14 and attached to theliquid-crystal panel W. The carrier film 14 previously produced in thecarrier film manufacturing line is wound into a roll by a lengthcorresponding to the wound length of the polarizing composite film 11.

In a process of producing a roll of provisional optical film inaccordance with embodiments illustrated in FIGS. 13 and 14, atransferable adhesive layer may be formed on the provisional opticalfilm in the same manner. In embodiments illustrated in FIGS. 13 and 14,when a provisional carrier film 14′ and/or a provisionalsurface-protection film 13′ are peeled, the adhesive layer formed on theprovisional carrier film 14′ is transferred to the polarizing compositefilm 11 so as to be incorporated into the polarizing composite film 11,in the same manner, as described below.

The roll of the carrier film 14 is mounted for rotation on a supportrack 571, and the carrier film 14 unrolled from the roll is releasablylaminated on the polarizing sheet 11′ by the carrier-film laminationmechanism 570. A releasable-film take up drive mechanism 572 is providedto take up a releasable film provided for protecting the adhesive layerformed on the carrier film 14 and to expose the adhesive layer when thecarrier film 14 is releasably laminated on the polarizing sheet 11′.

Referring to the flowchart of FIG. 15, in Step 1, the lamination drivemechanism 540 functions to laminate the protective film to one surfaceof the polarizer to thereby produce the polarizing sheet 11′ which isthen fed while being produced. In Step 2, defects existing in thepolarizing sheet 11′ thus produced and being fed are detected by theinspection unit 560. In Step 3, the roll of the carrier film 14 isrotatably mounted on the support rack 571. In Step 4, thereleasable-film take up drive mechanism 572 and the optical-film take updrive mechanism 580 functions to unroll the carrier film 14 formed withthe transferable adhesive layer from the roll with the adhesive layer inexposed state. In Step 5, the carrier film 14 is releasably laminated onthe polarizing sheet 11′ through the adhesive layer by the carrier-filmlamination mechanism 570, to form the polarizing composite film 11having the adhesive layer 12.

The information processing device 610 functions to define defective andnormal regions in the polarizing composite film 11 based on thelocations or coordinate positions of the defects detected in Step 2, andthen, based on the defined defective and normal regions, createsslit-position information for forming defective polarizing sheets X_(β)and normal polarizing sheets X_(α) in the polarizing composite film 11.In Step 6, the created slit-position information is recorded on asurface of the carrier film 14 laminated on the polarizing compositefilm 11, by the information recording unit 630. In Step 7, an opticalfilm formed through the above Steps is taken up by the optical-film takeup drive mechanism 580, to form a roll of the optical film laminate.

Although the descriptions have been made herein with respect to aprocess wherein the step of forming the adhesive layer 12 on thepolarizing composite film 11, simultaneously with the step of releasablylaminating the carrier film 14 on the adhesive layer 12, it is to beunderstood that the adhesive layer 12 may be previously formed on thepolarizing composite film 11. Further, in advance of Step 7, theadhesive surface of the surface-protection film 13 may be additionallylaminated on the surface of the polarizing composite film 11 opposite tothe surface on which the carrier film 14 is laminated by means of thesurface-protection-film lamination mechanism 640, irrespective ofwhether the protective film is subjected to the hard coating treatmentor the anti-dazzling or anti-glare treatment, before the protective filmis laminated to the polarizer. In this case, the resulting optical filmhas a structure having the carrier film 14 and the surface-protectionfilm 13 laminated on respective ones of the opposite surfaces of thepolarizing composite film 11.

(Manufacturing Method and System for Roll of Optical Film LaminateAccording to the Embodiment Illustrated in FIG. 13)

FIG. 13 is a schematic diagram showing the manufacturing system formanufacturing a roll of optical film laminate 10, wherein a roll of aprovisional optical film laminate 10′ is mounted on a support rack, theroll comprising a polarizing composite film 11 including a polarizerlaminated with a protective film, and a provisional carrier film 14′releasably laminated on the polarizing composite film 11 through anadhesive layer 12, and wherein a continuous web of the provisionaloptical film is continuously unrolled and the provisional carrier film14′ is peeled from the continuous web of the provisional optical film tobe subjected to an inspection for detecting defects existing in thepolarizing composite film 11 with the adhesive layer 12 in an exposedstate, a carrier film 14 being thereafter laminated in a releasablemanner on the adhesive layer 12 of the polarizing composite film 11, theslit-position information being recorded on a surface of the carrierfilm 14 in the same manner as in the embodiment illustrated in FIG. 12,to manufacture a roll of the optical film laminate 10. FIG. 16 isflowchart showing the manufacturing process or steps in the system.

It may be repeated that, in the process of producing the roll ofprovisional optical film laminate 10′, a transferable adhesive layer ispreliminary formed on the provisional carrier film 14′. Thus, when theprovisional carrier film 14′ is peeled from the continuous web of theprovisional optical film being continuously drawn from the roll, theadhesive layer formed on the provisional carrier film 14′ is transferredto the polarizing composite film so as to be incorporated into thepolarizing composite film 11. In place of the provisional carrier film14′ formed with the transferable adhesive layer, an adhesive layer 12may be previously formed on the polarizing composite film, and then aprovisional carrier film 14′ formed as a simple film subjected to areleasing treatment may be laminated to the adhesive layer 12. Further,a surface of the protective film to be laminated to the polarizer may besubjected to a hard coating treatment or an anti-dazzling or anti-glaretreatment.

The manufacturing system 500 for manufacturing a roll of optical filmlaminate 10 according to the present embodiment illustrated in FIG. 13comprises the following elements in common with the manufacturing systemaccording to the embodiment illustrated in FIG. 12; the inspection unit560 including the image-reading device 590 for detecting a defect ordefects existing in the polarizing composite film 11 including anadhesive layer 12; the carrier-film lamination mechanism 570 includingthe support rack 571 having the roll of the carrier film 14 mountedthereon for rotation; the optical-film take up drive mechanism 580 fordriving and taking up the produced optical film into a roll; the controlunit 600 including the information processing device 610 for performingan information processing and the storage device 620 for storing thereinprocessed information; and the information recording unit 630 forrecording encoded information on the optical film (final optical film).The manufacturing system 500 further comprises a lamination line orprovisional-optical-film feed line 530 including a support rack 531having a roll of the provisional optical film laminate 10′ mountedthereon for rotation, and a lamination drive mechanism 540 including apair of feeding drive rollers for continuously feeding the provisionaloptical film. The lamination drive mechanism 540 includes a distancemeasurement device 550 having an encoder incorporated in one of thefeeding drive rollers to calculate a feed-out distance in terms of alength from the leading edge of the provisional optical film.Additionally, the manufacturing system 500 comprises aprovisional-carrier-film peeling unit 575 including aprovisional-carrier-film take up drive mechanism 576.

Referring to the manufacturing process illustrated in FIG. 16, in Step1, the roll of the provisional optical film laminate 10′ is mounted inthe support rack 531. The provisional optical film comprises apolarizing composite film 11 including a polarizer having a protectivefilm laminated to one or each of opposite surfaces of the polarizer, anda provisional carrier film 14′ formed with a transferable adhesive layerand laminated to the polarizing composite film 11. In Step 2, acontinuous web of the provisional optical film is fed by the laminationdrive mechanism 540. In Steps 3 and 4, the provisional carrier film 14′is peeled and detached by the provisional-carrier-film take up drivemechanism 576 of the provisional-carrier-film peeling unit 575. In Step5, a defect or defects existing in the polarizing composite film 11 withthe adhesive layer 12 in an exposed state is detected by the inspectionunit 560.

The inspection unit 560 comprises an image-reading device 590 includingfor example a CCD camera. The image-reading device 590 is electricallyconnected to the information processing device 610 included in thecontrol unit 600, whereby in the image data read by the image-readingdevice 590 is processed in association with measurement data measured bythe distance measurement device 550 electrically connected to theinformation processing device 610. The control unit 600 functions tooperate the information processing device 610 and the storage device 620to process the image data from the image-reading device 590 inassociation with the measurement data on the transferred distancemeasured in terms of the length from the leading edge of the provisionaloptical film by the distance measurement device 550, so as to createposition data representing the locations or coordinate positions ofdefects in the polarizing composite film 11 having the adhesive layer inexposed state, and then store the position data in the storage device620. The control unit 600 is operable, based on the position data on thedetected defect locations or coordinate positions, to define defectiveregions and normal regions in the polarizing composite film 11. Further,the control unit 600 functions, based on the defective and normalregions defined in the polarizing composite film 11, to createslit-position information. The slit-position information is provided forindicating positions at which respective ones of the slit lines are tobe formed in the continuous web of optical film, and the slit lines areformed in pairs by the slitting unit 150 during the manufacturingprocess of liquid-crystal display elements, in such a manner that thecontinuous web of optical film being fed is slit in a directiontransverse to the feed direction at the two adjacent positions or theupstream and downstream positions to the feed direction to a depthreaching to the inner surface of the carrier film 14. The slit-positioninformation thus created is also stored in the storage device 620. Then,the information processing device 610 functions, based on the storedslit-position information, to create encoded information, together withadditional information, such as the manufacturing lot and the length inmeters of the web in the roll of the optical film, or in associationwith the additional information. The manner of creating the encodedinformation is common in embodiments illustrated in FIGS. 12-14 so thatit will be described below in connection with FIGS. 18 to 28.

In Steps 6 and 7, the carrier film 14 subjected to only a releasingtreatment is taken out by the carrier-film lamination mechanism 570which also serves as a film-feeding drive mechanism. In Step 8, thetaken out carrier film 14 is laminated to the exposed adhesive layer 12.The information processing device 610 defines defective regions andnormal regions in the polarizing composite film 11, based on thelocations or coordinate positions of the defects detected in Step 5, andthen, based on the defined defective and normal regions, createsslit-position information for forming defective polarizing sheets X_(β)and normal polarizing sheets X_(α) in the polarizing composite film 11.In Step 9, the created slit-position information is recorded on asurface of the carrier film 14 laminated on the polarizing compositefilm 11, by the information recording unit 630. In Step 10, the opticalfilm formed through the above Steps is wound by the optical-film take updrive mechanism 580 into a roll of the optical film laminate. Theembodiment illustrated in FIG. 13 is different from the embodimentillustrated in FIG. 12 in that the roll of the provisional optical filmlaminate 10′ is previously produced and prepared. Further, theembodiment illustrated in FIG. 13 is different from the embodimentillustrated in FIG. 12, in that when the provisional carrier film 14′having the transferable adhesive layer 12 provided thereon is peeled,the polarizing composite film 11 is formed, on the surface exposed bypeeling, with the transferred adhesive layer 12, and the inspection ofdefects existing in the polarizing composite film 11 is conducted on thepolarizing composite film having such exposed adhesive layer 12.

Although not illustrated in FIG. 13 or 16, it may be possible,particularly in the process of manufacturing roll of the provisionaloptical film laminate, in advance of Step 10, to laminate asurface-protection film 13 having an adhesive surface on the surface ofthe polarizing composite film 11 opposite to the surface on which thecarrier film 14 is laminated by means of a separately providedsurface-protection-film lamination mechanism 640, before the protectivefilm is laminated to the polarizer, irrespective of whether theprotective film is subjected to a hard coat treatment or ananti-dazzling or anti-glare treatment on one surface. In this case, theresulting optical film has a structure having the carrier film 14 andthe surface-protection film 13 laminated to respective ones of theopposite surfaces of the polarizing composite film 11.

(Manufacturing Method and System for Roll of Optical Film LaminateAccording to the Embodiment Illustrated in FIG. 14)

FIG. 14 is a schematic diagram showing the manufacturing system formanufacturing a roll of an optical film laminate 10, wherein a roll of aprovisional optical film laminate 10″ is mounted on a support rack, theprovisional optical film laminate comprising a polarizing composite film11 including a polarizer and a protective film laminated thereon, and aprovisional carrier film 14′ releasably laminated on the polarizingcomposite film 11 by an adhesive layer 12, and a provisionalsurface-protection film 13′ laminated by an adhesive surface on thesurface of the polarizing composite film 11 opposite to the surface onwhich the provisional carrier film 14′ is laminated, and wherein theprovisional carrier film 14′ and the provisional surface-protection film13′ are continuously peeled from the continuous web of the provisionaloptical film being continuously unrolled from the roll to have theadhesive layer exposed and the optical film having the exposed adhesivelayer is subjected to an inspection for the existence of defects in thepolarizing composite film 11, a carrier film 14 being then releasablylaminated on the adhesive layer 12 of the polarizing composite film 11,and a surface-protection film 13 being releasably laminated by theadhesive surface on the surface of the polarizing composite filmopposite to the surface on which the carrier film 14 is not laminated,in a sequential manner; slit-position information being thereafterrecorded on a surface of the carrier film 14 in the same manner as inembodiments illustrated in FIGS. 12 and 13. FIG. 17 is a flowchartshowing the manufacturing process or steps in the system.

It is to be repeated that, in the process of producing the roll of theprovisional optical film laminate 10′, a transferable adhesive layer ispreviously provided on the provisional carrier film 14′. Thus, when theprovisional carrier film 14′ is peeled from the continuous web of theprovisional optical film being continuously fed out from the roll, theadhesive layer formed on the provisional carrier film 14′ is transferredto the polarizing composite film 11 so as to be incorporated into thepolarizing composite film 11. In place of the provisional carrier film14′ formed with the transferable adhesive layer, an adhesive layer 12may be previously provided on the polarizing composite film, and then aprovisional carrier film 14′ may be laminated on the adhesive layer 12after being subjected to a releasing treatment. Further, as theprotective film to be attached to the polarizer, it may be possible touse a film which is subjected to a hard coat treatment or ananti-dazzling or anti-glare treatment at the surface to which thesurface-protection film is attached. The provisional surface-protectivefilm 13′ and the surface-protective film 13 are formed withnon-transferable adhesive surfaces at the sides which are to belaminated on the polarizing composite film 11. Typically, thesurface-protection film 13 is formed as a sheet integral with the normalpolarizing sheet of the polarizing composite film to be laminated to aliquid-crystal panel. Thus, the sheet of the surface-protection film 13having the adhesive surface is used as means to protect the surface ofan associated liquid-crystal display element during the manufacturingprocess of liquid-crystal display elements, and, after completion of themanufacturing process, it is peeled and removed together with theadhesive surface.

The manufacturing system 500 for manufacturing a roll of optical filmlaminate 10 according to the embodiment illustrated in FIG. 14,comprises a provisional-optical-film feed line 530 including a supportrack 531 having a roll of the provisional optical film laminate 10″rotatably mounted thereon as in the embodiment illustrated in FIG. 13,and the feed line 530 includes a lamination drive mechanism 540including a pair of feeding drive rollers for continuously feeding theprovisional optical film. The lamination drive mechanism 540 comprises adistance measurement device 550 having an encoder incorporated in one ofthe feeding drive rollers to calculate the delivered distance in termsof a length from the leading edge of the provisional optical film. Themanufacturing system 500 further comprises a provisional-carrier-filmpeeling unit 575 including a provisional-carrier-film take up drivemechanism 576. The manufacturing system 500 also comprises the followingelements as in the system according to the embodiment illustrated inFIG. 12; an inspection unit 560 including an image-reading device 590for inspecting existence of defects in the polarizing composite film 11;a carrier-film lamination mechanism 570 comprising a support rack 571having a roll of the carrier film 14 rotatably mounted thereon; anoptical-film take up drive mechanism 580 for drivingly winding theproduced optical film into a roll; a control unit 600 including aninformation processing device 610 for performing information processingand a storage device 620 for storing therein processed information; andthe information recording unit 630 for recording encoded information onthe optical film. Additionally, the manufacturing system 500 comprises aprovisional surface-protection-film peeling unit 645 including aprovisional surface-protection-film take up drive mechanism 646 fortaking up and peeling the provisional surface-protection film 13′, and asurface-protection-film lamination mechanism 640 for attaching the finalsurface-protection film 13 to the polarizing composite film at thesurface opposite to the surface on which the final carrier film 14 islaminated, the surface-protection-film lamination mechanism 640 alsoserving as a film-feeding drive mechanism.

Referring to the respective ones of the manufacturing steps illustratedin FIG. 17, in Step 1, the roll of the provisional optical film laminate10″ is mounted on the support rack 531. The provisional optical filmcomprises: a polarizing composite film 11 including a polarizer having aprotective film laminated to one or each of the opposite surfaces of thepolarizer, and a provisional carrier film 14′ formed with a transferableadhesive layer and laminated on the polarizing composite film 11. InStep 2, a continuous web of the provisional optical film is fed by thelamination drive mechanism 540. In Steps 3 and 4, the provisionalcarrier film 14′ is peeled and detached by the provisional-carrier-filmtake up drive mechanism 576 of the provisional-carrier-film peeling unit575. Next, in Steps 5 and 6, the provisional surface-protection film 13′which is laminated through an adhesive surface on the polarizingcomposite film at the surface on which the provisional carrier film 14′is laminated, is peeled and detached by the provisionalsurface-protection-film take up drive mechanism 646 of the provisionalsurface-protection-film peeling unit 645. In Step 7, an inspection isconducted by the inspection unit 560 on the polarizing composite film 11having the adhesive layer 12 in an exposed state, for existence ofdefects therein.

The inspection unit 560 comprises an image-reading device 590 includingfor example a CCD camera. The image-reading device 590 is electricallyconnected to the information processing device 610 included in thecontrol unit 600, wherein image data read by the image-reading device590 is processed in association with measurement data measured by thedistance measurement device 550 electrically connected to theinformation processing device 610. The control unit 600 is operable tocause the information processing device 610 and the storage device 620to process the image data from the image-reading device 590 inassociation with the measurement data relating to the delivered distancemeasured in terms of a length from the leading edge of the provisionaloptical film by the distance measurement device 550, so as to createposition data representing the location or coordinate position of thedefect in the polarizing composite film 11 having the adhesive layer 12,and then store the position data in the storage device 620. Then, thecontrol unit 600 functions, based on the position data relating to thedetected location or coordinate position of the defect, to define adefective region and a normal region in the polarizing composite film11. Further, the control unit 600 functions, based on the defective andnormal regions of the polarizing composite film 11 thus defined, tocreate slit-position information. The slit-position information isprovided for indicating positions at which respective ones of the slitlines are to be formed in the continuous web of optical film, and theslit lines are formed in pairs by the slitting unit 150 during themanufacturing process of liquid-crystal display elements, by cutting thecontinuous web of optical film being fed in a direction transverse tothe feed direction at the two adjacent positions or the upstream anddownstream positions in the feed direction to a depth reaching to theinward surface of the carrier film 14. The created slit-positioninformation is also stored in the storage device 620. Then, theinformation processing device 610 functions, based on the storedslit-position information, to create encoded information, together withadditional information, such as the manufacturing lot and the length inmeters of the optical film in the roll, or in association with theadditional information. The manner of creating the encoded informationis identical with those in embodiments illustrated in FIGS. 12-14, sothat it will be described below in connection with FIGS. 18 to 28.

In Steps 8 and 9, the carrier film 14 subjected only to a releasingtreatment is taken out by the carrier-film lamination mechanism 570which also serves as a film-feeding drive mechanism. In Step 10, thetaken out carrier film 14 is laminated on the exposed adhesive layer 12in a releasable manner. Further, in Steps 11 and 12, thesurface-protection film 13 having the adhesive surface is fed out by thesurface-protection-film lamination mechanism 640 which also serves asthe film-feeding drive mechanism. In Step 13, the fed finalsurface-protection film 13 is laminated through the adhesive surface onthe surface of the polarizing composite film opposite to the surface onwhich the carrier film 14 is laminated. This is the Step 13.

Then, the information processing device 610 functions to define adefective region and a normal region in the polarizing composite film11, based on the location or coordinate position of the defect detectedin Step 7, and then, based on the defined defective and normal regions,creates slit-position information for forming a defective polarizingsheet X_(β) and a normal polarizing sheet X_(α) in the polarizingcomposite film 11. In Step 14, the created slit-position information isrecorded on a surface of the carrier film 14 laminated on the polarizingcomposite film 11, by the information recording unit 630. Finally, inStep 15, the optical film formed through the above Steps is wound by theoptical-film take up drive mechanism 580, to form a roll of the opticalfilm laminate.

This embodiment is different from the embodiment illustrated in FIG. 13,in that the roll of the provisional optical film laminate 10″ ispreviously manufactured and prepared with a structure wherein not onlythe provisional carrier film 14′ but also the provisional surfaceprotection film 13′ are laminated on the polarizing composite film 11.Therefore, in this embodiment, the inspection of defects is carried outafter the adhesive layer 12 on the polarizing composite film 11 isexposed by sequentially peeling the provisional carrier film 14′ and theprovisional surface-protection film 13′.

In the embodiment illustrated in FIG. 12, the optical-film take up drivemechanism 580 is configured to operate in an inter-related manner withthe operation of at least the lamination drive mechanism 540, theinspection unit 560 and the carrier-film lamination mechanism 570, totake up the optical film having the encoded information 20 recorded on asurface of the carrier film 14. In embodiments illustrated in FIGS. 13and 14, the optical-film take up drive mechanism 580 is configured tooperate in an inter-related manner with at least the lamination drivemechanism 540, the take up drive mechanism (576, 646), the carrier-filmlamination mechanism 570 and the surface-protection-film laminationmechanism 640 to take up the optical film having the encoded information20 recorded on a surface of the carrier film 14. The manufacturingsystem 500 may be provided with a speed adjustment mechanism (not shown)including a feed roller in order to adjust the take up speed of theoptical film, when needed. Further, the encoded information may berecorded on the surface-protection film 13, instead of the carrier film14.

(Creation of Encoded Information)

An embodiment of creating the encoded information 20 includinginformation relating to the positions of the defects in the aboveembodiments is shown in the tables and schematic diagrams of FIGS. 22 to25. It is to be understood that the encoded information 20 may berecorded in variety of ways including, for example a mode in whichencoded information is entirely recorded on a single storage medium, anda mode in which encoded information is recorded on a plurality ofstorage media disposed at given intervals (e.g., at intervals of 1 m or100 m). The selection of the recording modes or the content of positioninformation to be stored as the encoded information may be determineddepending on the storage capacity and the function required for theliquid-crystal display element manufacturing method and system, and thelike.

Thus, it should be noted that embodiments illustrated in the schematicdiagram and the flowcharts of FIG. 18 and FIGS. 19 to 21 are shown onlyby way of examples.

The encoded information 20 comprises encoded information recorded on thecontinuous web unrolled from the roll of optical film laminate 10 and iscomprised of information for identifying the previously defineddefective and normal regions in the polarizing composite film 11including an adhesive layer 12, and slit-position information forforming defective and normal polarizing sheets corresponding to thedefective and normal regions, together with or in association withadditional information, such as the manufacturing lot and the length inmeters of the web in the roll. The encoded information 20 may be anytype of code, as long as it is readable by the reading unit 120 of thecontinuous manufacturing system 1 during the manufacturing process ofliquid-crystal display elements.

FIG. 18 is a schematic diagram showing the manner of calculating thepositions at which respective ones of the slit lines are to be formedfor delimiting the defective and normal regions in the continuous web ofoptical film which is being transported.

The control unit 600 functions to operate the information processingdevice 610 and the storage device 620 to process image data from theimage-reading device 590 in association with measurement data relatingto the feed-out distance measured in terms of a length from the leadingedge of the polarizing composite film 11 by the distance measurementdevice 550, so as to create position data representing the location orcoordinate position of a defect existing in the polarizing compositefilm, and then store the position data in the storage device 620. Then,the control unit 600 functions to define a defective region and a normalregion in the polarizing composite film 11, based on the position datarelating to the detected location or coordinate position of the defect.Further, the control unit 600 functions to create slit-positioninformation, based on the defective and normal regions of the polarizingcomposite film 11. The slit-position information is provided forindicating the positions at which respective ones of the slit lines areto be formed in the continuous web of optical film. The slit lines willbe formed in pairs by the slitting unit 150 during the manufacturingprocess of liquid-crystal display elements, by slitting the continuousweb of optical film being fed in a direction transverse to the feeddirection at the two adjacent positions or the upstream and downstreampositions to the feed direction to a depth reaching the inward surfaceof the carrier film 14. The created slit-position information is alsostored in the storage device 620. Then, the information processingdevice 610 operates to create encoded information based on the storedslit-position information, together with additional information, such asthe manufacturing lot and the length in meters of the web in the opticalfilm roll, or in association with additional information. FIGS. 19 to 21are flowcharts showing three different processes for calculating thepositions at which the respective ones of the slit lines are to beformed in the continuous web of optical film being fed.

The calculation processes will be described below based on the schematicdiagram of FIG. 18 and the flowcharts of FIGS. 19 to 21. The schematicdiagram of FIG. 18 shows the polarizing sheet 11′ including a polarizerhaving a protective film laminated thereon, or the polarizing compositefilm 11 having an adhesive layer (both the polarizing sheet 11′ and thepolarizing composite film 11 will hereinafter be referred collectivelyas “polarizing composite film 11”) being continuously fed in rightdirection by the feed roller of the carrier-film lamination mechanism570. However, in view of the fact that the optical film is formed by thecarrier-film lamination mechanism 570, by releasably laminating thecarrier film 14 with a transferable adhesive layer on the polarizingcomposite film 11 including the polarizer having the protective filmlaminated thereon, the polarizing composite film being continuouslysupplied by the feed roller will herein be referred generically as the“optical film”. The flowcharts of FIGS. 19 to 21 show a specific stepsup to the time when the encoded information 20 created by the controlunit 600 is recorded on the optical film, preferably, on the surface ofthe carrier film 14, and the optical film having the encoded informationrecorded thereon is taken up by the optical-film take up drive mechanism580.

In either case, in Step 1, the control unit 600 operates to instruct thelamination drive mechanism 540 and the optical-film take up drivemechanism 580 to feed the optical film. In Step 2, the control unit 600instructs the inspection unit 560 including the image-reading device 590to detect the location or coordinate position of a defect existing inthe optical film, and store the detected location or coordinate positionof the defect together with the type and size of the detected defect inthe storage device 620. In Steps 3 and 4, the control unit 600 functionsto determine the relationship between the length of a sheet of theoptical film and the length (X_(α)) corresponding to that of a normalregion. The method of determining the relationship is as follows insteps 3 to 5.

In Step 3, the control unit 600 functions to operate the informationprocessing device 610 to calculate the distance X between a referenceposition of the optical film being fed and the location of the defect,and store the calculated distance X in the storage device 620. As shownin FIG. 18, the distance X is a distance for example between theposition of the carrier-film lamination mechanism 570 (the referenceposition of the optical film) and the position of the inspection unit560 (or the image-reading device 590) (the defect position).

In Step 4, the control unit 600 further functions to operate theinformation processing device 610 to subtract the length (X_(α))corresponding to that of the normal region from the distance X to obtaina distance (X−X_(α))=X′, and then store the distance X′ in the storagedevice 620. The length (X_(α)) corresponding to that of the normalregion of the optical film is determined by a system manager based onthe size of the liquid-crystal panel and pre-stored in the storagedevice 620. Then, the control unit 600 functions to operate theinformation processing device 610 to determine whether the calculateddistance X is greater or less than the length (X_(α)) corresponding tothat of the normal region of the optical film.

Specifically, if it is established that the relation X′ (or X″) in FIG.18 >X_(α) is satisfied, then a length of optical film corresponding tothe normal region (X_(α)) of the optical film can be guaranteed, so thatthe control unit 600 instructs the lamination drive mechanism 540 andthe optical-film take up drive mechanism 580 to have the optical filmdelivered under tension by a length (X_(α)) corresponding to the normalregion. The value of the length (X_(α)) in this instance is theslit-position information for forming a normal polarizing sheet X_(α)corresponding to the normal region in the optical film.

Conversely, if it is established that the relation X′≦X_(α), i.e., X′″in FIG. 18 ≦X_(α), is satisfied then a length of optical filmcorresponding to the normal region (X_(α)) of the optical film cannot beguaranteed. In this instance, the region of the optical film having thelength (X_(β)) is a defective region (X_(β)), so that the control unit600 functions to operate the information processing device 610 tocalculate the length (X′+X₀)=X_(β) corresponding to the defective region(X_(β)) by adding a constant value X₀ to X′ (X′″ in FIG. 18), and toinstruct the lamination drive mechanism 540 and the optical-film take updrive mechanism 580 to feed the optical film under tension by the length(X_(β)) corresponding to the defective region. The value (X_(β)) in thisinstance is the slit-position information for forming a defectivepolarizing sheet X_(β) corresponding to the defective region of theoptical film.

Specifically, the control unit 600 operates to calculate the following(a) and (b) to create slit-position information indicative of thepositions at which respective ones of the slit lines are to be formed ina continuous web of the optical film to be fed during the manufacturingprocess of liquid-crystal display elements to form a normal polarizingsheet X_(α) and a defective polarizing sheet X_(β) of a polarizingcomposite film, and then store the slit-position information in thestorage device 620:

(a) a distance (X_(α)) to the position for forming a next slit line, ifX′>X_(α); and

(b) a distance (X′+X₀=X_(β)) to the position for forming a next slitline, if X′≦X_(α).

If the length (X′+X₀=X_(β)) corresponding to that of the defectiveregion becomes equal to the length (X_(α)) corresponding to that of thenormal region, i.e., if (X′+X₀)=(X_(α)), the control unit 600 cannotidentify or discriminate the normal region (X_(α)) over the defectiveregion (X_(β)). This means that the region to be recognized as thedefective region (X_(β)) may not be recognized as the defective region(X_(β)), so that, for example, the normal region (X_(α)) and thedefective region (X_(β)) cannot be discriminated from each other basedon measurement data on the feed-out distance of the optical film, andthe encoded information created based on the measurement data (X′+X₀)inevitably becomes imperfect. It is assumed that such a situation occurswhen the location or coordinate position of a defect in the optical filmis infinitely close to the position for forming a next slit line in theoptical film, or when a series of defects are distributed over a length(X_(α)) corresponding to that of the normal region.

In Step 5, if (X′+X₀) becomes equal to (X_(α)), the control unit 600functions to operate the information processing device 610 to perform acalculation based on at least one of the following methods to createinformation for identifying or discriminating the normal region (X_(α))over the defective region (X_(β)).

In Step 5 illustrated in FIG. 19, even if, as the result of calculationconducted by the information processing device 610, the distance (X′+X₀)to the position for forming a next slit line becomes equal to the length(X_(α)) corresponding to that of the normal region, the region in saiddistance is not essentially the normal region (X_(α)). In order to makeit possible to recognize such difference, for example, asdefect-including information X_(γ) illustrated in FIG. 23, a numericalsuffix “0” may be associated with the slit-position informationindicative of the position for forming a slit-line corresponding to thenormal region, and a numerical suffix “1” with the slit-positioninformation indicative of the position for forming a-slit-linecorresponding to the defective region. In Step 5 illustrated in FIG. 20,if, as a result of calculation of the information processing device 610,the distance (X′+X₀) to the position where a next-slit-line is to beformed becomes equal to the length (X_(α)) corresponding to that of thenormal region, an information processing is conducted so that thedistance to the position where a next-slit-line is to be formedsatisfies the relation (X′+X₀′), wherein X₀′>X₀, and store the distance(X′+X₀′) in the storage device 620. As shown in FIG. 24, thisinformation processing makes it possible by calculating the distance(X′+X₀′) different from X_(α), to allow the region having the length(X′+X₀′) to be identified or discriminated over the normal region(X_(α)). Further, in Step 5 illustrated in FIG. 21, if, as the result ofcalculation conducted by the information processing device 610, thedistance (X′+X₀) to the position where a next-slit-line is to be formedbecomes equal to the length (X_(α)) corresponding to that of the normalregion, an information processing is carried out to allow the distanceto the position where the next-slit-line is to be formed to become[(X′+X₀)/m], wherein m=2 or more, preferably 2 or 3, and store thedistance [(X′+X₀)/m] in the storage device 620. As the case of FIG. 20,this information processing illustrated in FIG. 25 is configured tocalculate the [(X′+X₀)/m] different from X_(α) to allow the regionhaving the length [(X′+X₀)/m] to be identified or discriminated over thenormal region (X_(α)).

Summarizing the above, in the process for creating information foridentifying or discriminating the defective and normal regions, eitherof the following methods may be adopted:

(1) A method of creating a defective identification information ordefect-including information X_(γ) as information for identifying ordiscriminating a region having a length (X′+X₀) calculated by theinformation processing device 610 over the normal region (X_(α));

(2) A method of creating a distance to the position where anext-slit-line is to be formed which is calculated by the informationprocessing device 610, as a distance (X′+X₀′) (wherein X₀′>X₀) which isdifferent from X_(α); and

(3) A method of creating a distance to the position where anext-slit-line is to be formed which is calculated by the informationprocessing device 610, as a distance [(X′+X₀)/m] (wherein m=2 or more)which is different from X_(α).

Particularly, in cases where the method (2) or (3) is employed,(X′+X₀)=(X_(α)) is changed to (X′+X₀′)≠X_(α) or [(X′+X₀)/m]≠X_(α) by theinformation processing illustrated in FIG. 20 or 21, the position wherea next-slit-line is to be formed can be used as information indicativeof the defective region identified or discriminated over the normalregion.

Next, in either case, in Step 6, the control unit 600 functions tooperate the information processing device 610 to determine the lengthbetween the reference position and the position where a next-slit-lineis to be formed, based on the calculation result in Steps 4 and 5. Inthe methods (2) or (3), in Step 7, the control unit 600 operates tocause the information processing device 610 to store the length to theposition where a next-slit-line is to be formed as determined in Step 6,in the storage device 620. However, in the method (1), the control unit600 functions to operate the information processing device 610 to storethe length to the position of forming a next-slit-line in associationwith the defect-including information X_(γ).

In either case, in Step 8, the control unit 600 functions to operate theinformation processing device 610 to convert, based on the position forforming a next-slit-line stored in Step 7, into encoded information, theslit-position information indicative of the position where a slit-lineis to be formed with respect to the leading edge of the optical filmbeing fed, together with or in association with additional information,such as the manufacturing lot and the length in meters of theoptical-film in the roll. In the method (1), it is to be understood thatthe defect-including information X_(γ) is simultaneously converted tothe encoded information.

In Step 9, the control unit 600 functions to operate the informationrecording unit 630 to record the encoded information converted in Step 8by the information processing device 610, on the optical film,preferably on the surface of the carrier film. In the method (1), itshould be understood that the encoded defect-including information X_(γ)is also recorded together with the encoded information. Finally, in Step10, the control unit 600 functions to operate the lamination drivemechanism 540 and the optical-film take up drive mechanism 580 to windthe finished optical film. The roll of the optical film laminate is thuscompleted. Examples of the encoded information are shown in FIGS. 22 to25.

(Details of the Manufacturing System for Roll of Optical Film LaminateSpecifically showing Defect Inspection Process)

With reference to FIGS. 26 and 27, a manufacturing system for a roll ofoptical film laminate will be more specifically described in connectionwith a specific method of inspecting defects existing in the polarizingcomposite film 11 having an adhesive layer 12. FIG. 26 is a schematicdiagram showing a manufacturing system 700 for a roll of optical filmlaminate having two inspection units, which is based on themanufacturing system according to the embodiment illustrated in FIG. 13.In the manufacturing process of the provisional optical film laminate10′, a polarizing sheet 11′ is formed with a structure comprising apolarizer having a protective film laminated on at least one of theopposite surfaces of the polarizer, and an adhesive layer 12 is formedon the other surface of the polarizing sheet 11′ to form a polarizingcomposite film 11. Then, a provisional carrier film 14′ is releasablylaminated on the adhesive layer 12 of the polarizing composite film 11,and the resulting provisional optical film is wound into a roll to formthe roll of the provisional optical film laminate 10′. The roll of theprovisional optical film laminate 10′ is rotatably mounted on a supportrack 711 of a provisional-optical-film feed unit 710. In addition to theprovisional-optical-film feed unit 710, the manufacturing system 700comprises a provisional-carrier-film take up drive mechanism 720, afirst inspection unit 730, a second inspection unit 731, a control unit740, a carrier-film feed unit 750, a carrier-film lamination mechanism760, an optical-film take up drive mechanism 770, and an informationrecording unit 780.

The provisional optical film is continuously delivered from the roll ofthe provisional optical film laminate 10′ by theprovisional-optical-film feed unit 710. The provisional-carrier-filmtake up drive mechanism 720 is disposed along the feed direction of theprovisional optical film, and adapted to take up the provisional carrierfilm 14′ by peeling and detaching it from the provisional optical film.Each of the first and second inspection units 730, 731 is adapted todetect one or more defects in the surface and the interior of thepolarizing composite film 11 with the adhesive layer 12 exposed as aresult of the peeling the provisional carrier film 14′. The firstinspection unit 730 is comprised of a transmission inspection deviceillustrated in FIG. 28. The transmission inspection method is designedsuch that visible light emitted from a light source is projected to thepolarizing composite film 11 perpendicular thereto, and to have thelight which has passed through the polarizing composite film 11 beingreceived by an optical detection unit to detect one or more defectsexisting in the polarizing composite film 11 in the form of a shade orshadow. The second inspection unit 731 is comprised of a cross-Nicoltransmission inspection device illustrated in FIG. 28. The cross-Nicoltransmission inspection method is designed such that visible lightemitted from a light source is introduced perpendicularly or obliquelyinto a polarization filter which is disposed immediately before anoptical detection unit in such a manner that the absorption axis of thepolarization filter is oriented at a right angle with respect to theabsorption axis of the polarizing composite film, the light which haspassed through the polarizing composite film being received by theoptical detection unit to detect the defect in the polarizing compositefilm as a bright spot.

The control unit 740 functions to operate an information processingdevice 741 to define a defective region and a normal region in thepolarizing composite film 11, based on the location or coordinateposition of the defect detected by the first inspection unit 730 and thesecond inspection unit 731. Then, the control unit 740 functions tooperate an information processing device 741 to create slit-positioninformation for forming a defective polarizing sheet X_(β) and a normalpolarizing sheet X_(α) in the polarizing composite film 11, based on thedefined defective and normal regions, and convert the slit-positioninformation into encoded information 20. The information recording unit780 is adapted to record the encoded information on a surface of thecarrier film 14 newly laminated on the polarizing composite film 11.

The carrier-film feed unit 750 disposed downstream the second inspectionunit 731 is adapted to continuously unroll the carrier film 14 from aroll of the carrier film 14 rotatably mounted in the support rack 751,along the feed direction of the polarizing composite film 11. Thecarrier-film lamination mechanism 760 is provided with a pair ofrollers, and adapted to releasably laminate the carrier film 14 on theexposed adhesive layer 12 after completion of the inspection by theinspection units. It may be repeated that, the encoded information isrecorded on the surface of the carrier film 14 newly laminated on theadhesive layer, by the information recording unit 780. The createdoptical film is wound by the optical-film take up drive mechanism 770into a roll, and then formed into a roll of the optical film laminate10. The control unit 740 functions to control respective operations ofthe units, the mechanisms and the device in an inter-related manner.

FIG. 27 is a schematic diagram showing a manufacturing system 800 of aroll of optical film laminate having four inspection units, which isbased on the manufacturing system according to the embodimentillustrated in FIG. 14.

In the manufacturing process of a roll of the provisional optical filmlaminate 10″, a polarizing sheet 11′ is formed as comprising a polarizerhaving a protective film laminated on at least one of the oppositesurfaces of the polarizer, and an adhesive layer 12 is formed on theother surface of the polarizing sheet 11′ to form a polarizing compositefilm 11. Then, a provisional carrier film 14′ is releasably laminated onthe adhesive layer 12 of the polarizing composite film 11, and aprovisional surface-protection film 13′ is releasably laminated on thesurface of the polarizing composite film 11 opposite to the surface onwhich the provisional surface-protection film 13′ is laminated. Theresulting provisional optical film is wound into a roll to form the rollof the provisional optical film laminate 10″. The roll of provisionaloptical film laminate 10″ is rotatably mounted in a support rack 811 ofa provisional-optical-film feed unit 810.

The manufacturing system 800 comprises in addition to theprovisional-optical-film feed unit 810, a provisional-carrier-film takeup drive mechanism 820, a provisional-surface-protection-film take updrive mechanism 830, a first inspection unit 840, a second inspectionunit 850, a third inspection unit 851, a fourth inspection unit 852, acontrol unit 860, a provisional-surface-protection-film feed unit 870, acarrier-film feed unit 880, two sets of lamination mechanisms 890(carrier-film lamination mechanism 891, surface-protection-filmlamination mechanism 892), an optical-film take up drive mechanism 910,and an information recording unit 920.

The provisional optical film is continuously unrolled from the roll ofthe provisional optical film laminate 10″ by theprovisional-optical-film feed unit 810. Theprovisional-surface-protection-film take up drive mechanism 830 isdisposed along the feed direction of the provisional optical film, andadapted to take up the provisional surface-protection film 13′ bypeeling and detaching it from the provisional optical film. Theprovisional-carrier-film take up drive mechanism 820 is disposeddownstream the provisional-surface-protection-film take up drivemechanism 830 and along the feed direction of the provisional opticalfilm, and adapted to take up the provisional carrier film 14′ by peelingand detaching it from the provisional optical film.

As shown in FIG. 27, the inspection units are disposed at respectivefour positions in the manufacturing system 800. The first inspectionunit 840 is located between the provisional-surface-protection-film takeup drive mechanism 830 and the provisional-carrier-film take up drivemechanism 820, and adapted to inspect the provisional optical film in astate where only the provisional surface-protection film 13′ is peeledoff and the provisional carrier film 14′ is still on the web.Specifically, the inspection is made to detect one or more defects inthe surface of the polarizing composite film 11, based on the reflectedlight from the protective film of the exposed polarizing composite film11. The second inspection unit 850, the third inspection unit 851 andthe fourth inspection unit 852 are located between theprovisional-carrier-film take up drive mechanism 820 and thecarrier-film feed unit 880, so that they inspect one or more defects onthe surface and the interior of the polarizing composite film by havinglight transmit through the polarizing composite film 11 having theadhesive layer 12 in exposed state as a result of the peeling theprovisional carrier film 14′ by the provisional-carrier-film take updrive mechanism 820.

More specifically, each of the second to fourth inspection units isconfigured as follows. The second inspection unit 850 is designed forthe transmission inspection illustrated in FIG. 28. The transmissioninspection method is designed such that visible light emitted from alight source is projected to the polarizing composite film 11perpendicular thereto, and to have the light which has passed throughthe polarizing composite film 11 being received by an optical detectionunit to detect one or more defects existing in the polarizing compositefilm 11 in the form of a shade or shadow. The third inspection unit 851is designed for the oblique transmission inspection illustrated in FIG.28. The oblique transmission inspection method is designed such that avisible light emitted from an oblique-transmission light source isprojected to the polarizing composite film 11 in an oblique angle and tohave the light which has passed through the polarizing film received byan optical detection unit to detect one or more defects existing in theoptical film as a shade. The fourth inspection unit 852 is comprised ofa cross-Nicol transmission inspection device illustrated in FIG. 28. Thecross-Nicol transmission inspection method is designed such that avisible light emitted from a light source is projected to the polarizingcomposite film perpendicularly or obliquely thereto and, with apolarization filter being disposed immediately before an opticaldetection unit with an absorption axis thereof being oriented at a rightangle with respect to an absorption axis of the polarizing compositefilm, the light which has passed through the polarizing composite filmis received by the optical detection unit to thereby detect one or moredefects existing in the polarizing composite film as one or more brightspots.

The control unit 860 functions to operate an information processingdevice 861 to define in the polarizing composite film 11 a defectiveregion and a normal region, based on the location or coordinate positionof a defect or defects detected by the first inspection unit 840, thesecond inspection unit 850, the third inspection unit 851 and the fourthinspection unit 852. Then, the control unit 860 functions to operate aninformation processing device 861 to create slit-position informationfor forming a defective polarizing sheet X_(β) and a normal polarizingsheet X_(α) in the polarizing film, based on the defined defective andnormal regions, and convert the slit-position information into encodedinformation 20. The information recording unit 920 is adapted to recordthe encoded information 20 on a surface of the carrier film 14 newlylaminated to the polarizing composite film 11.

The carrier-film feed unit 880 disposed downstream the fourth inspectionunit 852 is adapted to continuously unroll the carrier film 14 from theroll of the carrier film laminate 14 rotatably mounted in a support rack881, along the feed direction of the polarizing composite film 11. Theprovisional-surface-protection-film feed unit 870 disposed downstreamthe carrier-film feed unit 880 is adapted to continuously unroll thesurface-protection film 13 from a roll of the surface-protection film 13rotatably loaded in a support rack 871, along the feed direction of thepolarizing composite film 11. The lamination mechanisms 890, or thecarrier-film lamination mechanism 891 and the surface-protection-filmlamination mechanism 892 each having a pair of rollers function toreleasably laminate the carrier film 14 and the surface-protection film13 respectively on the exposed adhesive layer 12 and the surface of thepolarizing composite film which does not have an adhesive layer, aftercompletion of the inspection by the inspection units disposed at thefour positions. It may be repeated that, the encoded information isrecorded on the surface of the carrier film 14 newly laminated on theadhesive layer, by the information recording unit 920. The createdoptical film is wound by the optical-film take up drive mechanism 910,and formed into a roll of optical film laminate 10. The control unit 860is operable to control respective operations of the units, themechanisms and device in an inter-related manner.

Although at least one embodiment has been described in connection withpreferred embodiments thereof, it will be appreciated that variouschanges and modifications will be made by those skilled in the artwithout departing from the spirit and scope of the invention, defined inthe following claims, and legal equivalents of the following claims maybe substituted for elements thereof. Accordingly, the present inventionis not limited to the specific embodiments disclosed as the best modefor carrying out the invention, but intended to cover all embodimentsincluded within the scope thereof.

1. A method of producing a roll of optical film laminate for use in a continuous manufacturing system for liquid-crystal display elements, wherein the manufacturing system is operative to produce liquid-crystal display element by adhesively attaching a polarizer to each of the opposite surfaces of a liquid crystal panel which is of a rectangular shape having a long side dimension and a short side dimension, the method comprising the steps of: (a) laminating a protective film fed from a roll of the protective film, on at least one of opposite surfaces of a continuous layer of polarizer fed from a roll of a continuous layer of the polarizer, to form a polarizing composite film, (b) inspecting surfaces and inside of the formed polarizing composite film to detect a location or coordinate position of a defect existing in the polarizing composite film, (c) releasably laminating a carrier film fed from a roll of the carrier film, on the polarizing composite film in which the location or the coordinate position of the defect has been determined, to form a continuous web of optical film, said continuous web of optical film having a longitudinal direction and a transverse direction which is perpendicular to said longitudinal direction, and further having a width corresponding to one of said long or short side dimension, (d) defining a plurality of slit positions for determining positions of slit lines each extending in said transverse direction throughout the width of said web of optical film to define rectangular regions each between two longitudinally adjacent slitting positions, said rectangular regions including a defective region and a normal region in said polarizing composite film, based on the location or coordinate position of the defect existing in the polarizing composite film and detected by the inspection, the defect-free, normal regions each having a longitudinal dimension corresponding to the other of said long or short side dimension of the liquid crystal panel, and producing encoded information based on the defective and normal regions, said encoded information including slit-position information indicative of positions at which the respective slit lines are to be formed in the continuous web of optical film by a slitting unit of the continuous manufacturing system, (e) recording the produced encoded information on the continuous web of optical film, in a manner readable by a reading unit of the continuous manufacturing system, and (f) after the encoded information is recorded on the continuous web of optical film, winding the continuous web of optical film into a roll to form a roll of optical film laminate.
 2. The method as defined in claim 1, wherein the encoded information further includes information for identifying the defective region and the normal region of the polarizing composite film.
 3. The method as defined in claim 1, wherein the step of forming the web of optical film includes a further step of releasably laminating a surface-protection film having an adhesive surface on the polarizing composite film at a surface opposite to a surface on which the carrier film is releasably laminated.
 4. The method as defined in claim 3, wherein the encoded information is recorded on the carrier film or the surface-protection film.
 5. The method as defined in claim 1, wherein the carrier film has a transferable adhesive layer formed by, after subjecting one surface of the carrier film to a releasing treatment, applying a solvent containing an adhesive to the treated surface, and drying the solvent.
 6. The method as defined in claim 1, wherein the step of detecting the location or the coordinate position of the defect includes a first inspection sub-step of primarily inspecting a surface of the polarizing composite film by means of reflected light, and a second inspection sub-step of primarily inspecting the inside of the polarizing composite film by means of transmission or cross-Nicol transmission.
 7. The method as defined in claim 1, wherein the polarizing composite film having a width conforming to a long or short side of each of the liquid-crystal display elements.
 8. A method of producing a roll of optical film laminate for use in a continuous manufacturing system for liquid-crystal display elements, wherein the manufacturing system is operative to produce liquid-crystal display element by adhesively attaching a polarizer to each of the opposite surfaces of a liquid crystal panel which is of a rectangular shape having a long side dimension and a short side dimension, the method comprises the steps of: (a) providing a roll of provisional optical film laminate comprising a polarizing composite film which comprises a laminate of a continuous layer of a polarizer layer and a protective film laminated on at least one surface of the continuous layer of the polarizer, and an adhesive layer provided on one of opposite surfaces of the laminate, a provisional carrier film being releasably laminated on the adhesive layer, (b) removing and winding the provisional carrier film from the provisional optical film laminate supplied from the roll of the provisional optical film laminate provided in the preceding step, to feed the polarizing composite film with the adhesive layer in an exposed state, (c) inspecting one or both surfaces and inside of the polarizing composite film with the adhesive layer in the exposed state to detect a location or coordinate position of a defect existing in the polarizing composite film having the adhesive layer, (d) releasably laminating, after the location or coordinate position of the defect in the polarizing composite film having the adhesive layer is detected, a carrier film supplied from a roll of carrier film, to the polarizing composite film through the adhesive layer, to form a continuous web of optical film, said continuous web of optical film having a longitudinal direction and a transverse direction which is perpendicular to said longitudinal direction, and further having a width corresponding to one of said long or short side dimension, (e) defining a plurality of slit positions for determining positions of slit lines each extending in said transverse direction throughout the width of said web of optical film to define rectangular regions each between two longitudinally adjacent slitting positions, said rectangular regions including a defective region and a defect-free, normal region, based on the location or coordinate position of the defect in the polarizing composite film, the defect-free, normal regions each having a longitudinal dimension corresponding to the other of said long or short side dimension of the liquid crystal panel and, based on the defective and normal regions, producing encoded information including slit-position information indicative of positions at which the respective slit lines are to be formed in the continuous web of optical film by a slitting unit of the continuous manufacturing system, (f) recording the produced encoded information on the continuous web of optical film, in a manner readable by a reading unit of the continuous manufacturing system, and (g) after the encoded information is recorded on the continuous web of optical film, winding the continuous web of optical film into a roll to form a roll of the optical film laminate.
 9. The method as defined in claim 8, wherein the encoded information further includes information for identifying the defective region and the normal region of the polarizing composite film.
 10. The method as defined in claim 8, wherein the step of forming the continuous web of optical film comprises a further step of releasably laminating a surface-protection film having an adhesive surface on the polarizing composite film at a surface opposite to a surface on which the carrier film is releasably laminated through the adhesive layer.
 11. The method as defined in claim 10, to wherein the encoded information is recorded on the carrier film or the surface-protection film.
 12. The method as defined in claim 8, wherein the provisional carrier film has a transferable adhesive layer formed by, after subjecting one surface of the provisional carrier film to a releasing treatment, applying a solvent containing an adhesive to the treated surface, and drying the solvent.
 13. The method as defined in claim 8, wherein the carrier film is subjected to only a releasing treatment at a surface through which the carrier film is releasably laminated on the polarizing composite film which has been fed with the adhesive layer in an exposed state.
 14. The method as defined in claim 8, wherein the step of detecting the location or the coordinate position of the defect includes a first inspection sub-step of primarily inspecting a portion of a surface of the polarizing composite film devoid of the adhesive layer by means of reflected light, and a second inspection sub-step of primarily inspecting the inside of the polarizing composite film by means of transmission or cross-Nicol transmission.
 15. The method as defined in claim 8, wherein the polarizing composite film has a width conforming to a long or short side of each of the liquid-crystal display elements.
 16. A system for producing a roll of an optical film laminate for use in a continuous manufacturing system for liquid-crystal display elements, wherein the manufacturing system is operative to produce liquid-crystal display element by adhesively attaching a polarizer to each of the opposite surfaces of a liquid crystal panel which is of a rectangular shape having a long side dimension and a short side dimension, the manufacturing system comprising: (a) a polarizing composite film forming unit including a lamination mechanism for laminating a continuous layer of polarizer to a protective film, said polarizing composite film forming unit being adapted to laminate a protective film fed from a roll of the protective film to at least one surface of a continuous layer of polarizer fed from a roll of the continuous polarizer layer, to form a continuous web of polarizing composite film, (b) a polarizing-film inspection unit adapted to inspect surface and inside of the formed polarizing composite film to detect a location or coordinate position of a defect existing in the polarizing composite film, (c) an optical-film forming unit including a lamination mechanism for laminating the polarizing composite film to a carrier film, the optical-film forming unit being adapted, after the location or coordinate position of the defect in the polarizing composite film is detected, to releasably laminate a carrier film fed from a roll of the carrier film, to the polarizing composite film to form a continuous web of optical film, said continuous web of optical film having a longitudinal direction and a transverse direction which is perpendicular to said longitudinal direction, and further having a width corresponding to one of said long or short side dimension, (d) an information processing device adapted for defining a plurality of slit positions for determining positions of slit lines each extending in said transverse direction throughout the width of said web of optical film to define rectangular regions each between two longitudinally adjacent slitting positions, said rectangular regions including a defective region and a defect-free, normal region in said polarizing composite film, based on the location or coordinate position of the defect existing in the polarizing composite film, the defect-free, normal regions each having a longitudinal dimension corresponding to the other of said long or short side dimension of the liquid crystal panel and based on the defective and normal regions, producing encoded information including slit-position information indicative of positions at which the respective slit lines are to be formed in the continuous web of optical film by a slitting unit of the continuous manufacturing system, (e) an information recording unit adapted to record the produced encoded information on the continuous web of optical film, in a manner readable by a reading unit of the continuous manufacturing system, (f) a winding drive mechanism adapted, after the encoded information is recorded on the continuous web of optical film, to wind the continuous web of optical film into a roll to form a roll of the optical film laminate, and (g) a control unit adapted to control respective operations of at least the polarizing-film forming unit, the polarizing-film inspection unit, the optical-film forming unit, the information processing device, the information recording unit and the winding drive mechanism, in an inter-related manner.
 17. The system as defined in claim 16, wherein the encoded information further includes information for identifying the defective region and the normal region of the polarizing composite film.
 18. The system as defined in claim 16, wherein the optical-film forming unit further includes a lamination mechanism for laminating the polarizing composite film to a surface-protective film, the lamination mechanism being adapted to releasably laminate a surface-protection film having an adhesive surface on the polarizing composite film at a surface opposite to a surface on which the carrier film is releasably laminated.
 19. The system as defined in claim 18, wherein the encoded information is recorded on the carrier film or the surface-protection film.
 20. The system as defined in claim 16, wherein the polarizing-film inspection unit includes a first inspection sub-unit adapted to primarily inspect the surface of the polarizing composite film by means of reflected light, and a second inspection sub-unit adapted to primarily inspect the inside of the polarizing composite film by means of transmission or cross-Nicol transmission.
 21. The system as defined in claim 16, wherein the polarizing composite film has a width conforming to a long or short side of each of the liquid-crystal display elements.
 22. A system for producing a roll of an optical film laminate for use in a continuous manufacturing system for liquid-crystal display elements, wherein the manufacturing system is operative to produce liquid-crystal display element by adhesively attaching a polarizer to each of the opposite surfaces of a liquid crystal panel which is of a rectangular shape having a long side dimension and a short side dimension, the manufacturing system comprising: (a) a provisional-optical-film feed unit adapted to work with a roll of provisional optical film laminate and adapted to feed a provisional optical film from the roll of the provisional optical film laminate, said provisional optical film comprising a polarizing composite film including a laminate of a continuous layer of a polarizer and a protective film laminated on at least one surface of the continuous layer of the polarizer, and an adhesive layer provided on at least one surface of the laminate, said provisional optical film further including a provisional carrier film laminated on the adhesive layer of the polarizing composite film, (b) a provisional-carrier-film detaching unit adapted for detaching the provisional carrier film from the provisional optical film supplied from the roll of the provisional optical film to have the adhesive layer exposed, and feeding the polarizing composite film with the adhesive layer in an exposed state, (c) a polarizing-film inspection unit adapted to inspect surface and inside portions of the polarizing composite film which has been supplied with the adhesive layer in the exposed state, to detect a location or coordinate position of a defect existing in the polarizing composite film having the adhesive layer, (d) an optical-film forming unit including a lamination mechanism for laminating the polarizing composite film having said adhesive layer to a carrier film by releasably laminate, through the adhesive layer, the carrier film supplied from a roll of the carrier film on said polarizing composite film in which the location of the defect existing in the polarizing composite film has been detected, to form a continuous web of an optical film, said continuous web of optical film having a longitudinal direction and a transverse direction which is perpendicular to said longitudinal direction, and further having a width corresponding to one of said long or short side dimension, (e) an information processing device adapted for defining a plurality of slit positions for determining positions of slit lines each extending in said transverse direction throughout the width of said web of optical film to define rectangular regions each between two longitudinally adjacent slitting positions, said rectangular regions including a defective region and a normal region in the polarizing composite film including the adhesive layer, based on the location of the detected defect existing in the polarizing composite film, the defect-free, normal regions each having a longitudinal dimension corresponding to the other of said long or short side dimension of the liquid crystal panel and, based on the defective and normal regions, producing encoded information including slit-position information indicative of positions at which the respective slit lines are to be formed in the continuous web of optical film by a slitting unit of the continuous manufacturing system, (f) an information recording unit adapted to record the produced encoded information on the continuous web of optical film, in a manner readable by a reading unit of the continuous manufacturing system, (g) a winding drive mechanism adapted, after the encoded information is recorded on the continuous web of optical film, to wind the continuous web of optical film into a roll to form a roll of the optical film laminate, and (h) a control unit adapted to control respective operations of at least the provisional-optical-film feed unit, the provisional-carrier-film detaching unit, the polarizing-film inspection unit, the optical-film forming unit, the information processing device, the information recording unit and the winding drive mechanism, in an inter-related manner.
 23. The system as defined in claim 22, wherein the encoded information further includes information for identifying the defective region and the normal region of the polarizing composite film.
 24. The system as defined in claim 22, wherein the optical-film forming unit further includes a lamination mechanism for laminating a surface-protection film on said polarizing composite film having said adhesive layer, the lamination mechanism being adapted to releasably laminate the surface-protection film having an adhesive surface on the polarizing composite film at a surface opposite to a surface on which said carrier film is releasably laminated.
 25. The system as defined in claim 24, wherein the encoded information is recorded on the carrier film or the surface-protection film.
 26. The system as defined in claim 22, wherein the polarizing composite film inspection unit includes a first inspection sub-unit adapted to primarily inspect the surface of the polarizing composite film having the adhesive layer by means of reflected light, and a second inspection sub-unit adapted to primarily inspect the inside of the polarizing composite film having the adhesive layer by means of transmission or cross-Nicol transmission.
 27. The system as defined in claim 22, wherein the polarizing composite film has a width conforming to a long or short side of each of the liquid-crystal display elements. 